The Torah introduces a halachic mechanism in which the minority is nullified in the majority called Bitul. 
Introduction to Taste of Forbidden Foods
- There’s a dispute between Rashi and Tosfot whether we consider the taste of a forbidden food like the actual forbidden food itself on a biblical level or only on a rabbinic level. Rashi holds it is only rabbinic and Tosfot holds it is biblical. One ramification of this is if there’s a mixture of a forbidden food in a liquid mixture of another taste which was permitted, if it is unclear whether there is sixty times the volume of the forbidden food according to Rashi it is permitted and according to Tosfot it is forbidden. We hold like Tosfot.
- A food that fell into a mixture and was nullified and then falls into another mixture that second mixture is also forbidden unless there’s nullification.  However, if that item fell back into that same mixture it is still nullified with the original sixty times the forbidden item.
- Forbidden foods require sixty times for nullification even if it less than the requisite amount of a kezayit.
- Spices which are intrinsically forbidden aren’t nullified in sixty as long as their taste is recognizable. 
- If the forbidden item in a mixture is recognizable it must be removed. 
- If the forbidden food is recognizable even if its taste is nullified it must be removed. If the forbidden food isn’t currently recognizable but it is possible to remove the forbidden food nonetheless, one should do so. For example, if forbidden fat was cooked into a mixture but it can be removed by pouring water into it and letting the fat rise one should do so. There is a dispute if one needs to do so if in the process the whole mixture will be ruined. Some poskim advise being strict.
- A forbidden food that fell into a mixture of permitted food that shares its taste is nullified biblically as long as there’s a majority and according to the rabbis requires nullification of one to sixty to be permitted. However, if that forbidden food fell into a mixture of permitted food with a different taste than it, it would require nullification of one to sixty on a biblical level. 
- For example, meat and fat are considered different types of food unless the meat is very fatty.
- Since everything is really dependent on taste, theoretically it would be sufficient to taste the mixture to see if there’s still any taste of the forbidden food in the mixture. However, since it is forbidden to taste, the next option is to give it to a non-Jew to taste. The practice is not to rely on the non-Jew for this matter. In fact there’s a dispute in the poskim whether one can rely on the tasting of an another Jew in cases where it is permitted to taste it and we hold that initially one should not rely on that either.
- If non-Kosher solid food is mixed up in a simple majority (51%) of Kosher food, and the non-Kosher food is similar in taste to the non-Kosher piece, is unrecognizable in the mixture, and the mixture is not hot or cooked together, then mixture as a whole is permissible. Nonetheless, one person may only eat the pieces one at a time. Some say that one person shouldn’t eat all of them but rather two or more people should split it up. A stringency would be to take one of the pieces and throw it out or throw it to the dogs.
- If the pieces have different tastes in order to have nullification there needs to be sixty times the amount of forbidden food added to the mixture. This applies equally if it is rabbinic prohibition mixed into the mixture of different types.
- If the dry mixture which had nullification was later cooked together it becomes forbidden.
- When a mixture is permissible because of nullification one person may eat the entire mixture at different intervals and not all at once. It is preferable for one Jew not to eat the entire mixture but rather leave one piece and let another person eat it. It is even more meritorious to be strict to discard one piece or to give it to a non-Jew. 
- Some have the practice to boil 3 eggs at a time so that if one is found with a blood spot, it will be nullified and not make the pot non-kosher. Some note that this practice is not necessary nowadays when the eggs are not fertilized.
- There is a dispute whether nullification requires that there is a majority in quantity of permitted pieces as well as majority of volume of permitted pieces or merely that one needs a majority in quantity of permitted pieces.
Liquid and Solid Mixtures
- If a mixture has solids that dissolved completely they are treated like liquid mixtures.
- If a mixture has solids that are recognizably separate from the liquid the mixture is treated as both a mixture of solids and liquids. In order to permit eating the liquid there needs to be sixty in the whole mixture in comparison to the forbidden ingredients. If there is a solid non-kosher ingredient and it is recognizable it needs to be removed. If it isn't recognizable and there are other comparable kosher solid ingredients if there are a majority of the solid ingredients the solids can be eaten if there is also sixty in the entire mixture compared to the forbidden ingredients. If there isn't majority the solid ingredients are forbidden even if there is sixty in the entire mixture compared to the forbidden ingredients.
- If the solid pieces of non-kosher in the liquid mixture are crushed up into small pieces but are recognizable they should be strained out. If that is impossible some say that it is forbidden.
- If the mixture comprised of either 1) foods of dissimilar taste, 2) liquids, or 3) solids that were hot or cooked together, the nullification required is 1 to 60 called Bitul BeSheshim. 
- Nullification of 60 means that the volume of permitted ingredients is 60 times the volume of the forbidden ingredients.
- If solid foods which were cold and of similar taste are subsequently cooked together the nullification required is Bitul BeShishim. According to Ashkenazim in cases of loss it’s permissible to use the nullification of Bitul BeRov if one knew at first that there was a mixture of non-Kosher and Kosher prior to the mixture being cooked. 
- If something forbidden was cooked together with permitted food even if the forbidden item is recognizable and is removed, the mixture is forbidden unless the permitted part of the mixture is sixty times the volume of the forbidden part.
- Even if it is a rabbinic prohibition or isn't a requisite size of prohibited foods (shiur), sixty times the amount of forbidden ingredients are needed to nullify them.
Min Bmino Veino Mino
- If there's a mixture of like tasting ingredients and unlike tasting ingredients and the forbidden ingredient isn't recognizable. If (1) the volume of the like-tasting ingredient is greater than the volume of the forbidden ingredient and (2) the volume of the permitted ingredients, both those of similar and dissimilar tastes, is sixty times that of the forbidden ingredient the mixture is permitted.
- If there's a mixture of like tasting ingredients and unlike tasting ingredients and the forbidden ingredient isn't recognizable. If (1) the volume of the like-tasting ingredient is equal to or less than the volume of the forbidden ingredient but (2) the volume of the permitted ingredients, both those of similar and dissimilar tastes, is sixty times that of the forbidden ingredient, some poskim hold that the the mixture is permitted, while others argue.
Foods with a Higher Ratio of Nullification
- Certain prohibited foods require a higher ratio for nullification. For example, Trumah, Challah, and Bikkurim require a 1 (forbidden) to 100 (permitted) ratio and Orlah and Kelayim require a 1 to 200 ratio. 
Awareness of the Nullification
- A necessary factor for nullification to take place is that a person must realize that the nullification occurred. However, if a person doesn't realize that the nullification occurred until the situation is further complicated the original nullification is ineffective. Most poskim say that the requirement of awareness is biblical, while some argue it is only rabbinic.
- For example, if one piece of non-Kosher meat was mixed with two Kosher pieces and before he realized that non-Kosher was mixed up with the Kosher pieces he cooked them all together they are all considered non-Kosher. However, if he realized that the non-Kosher was mixed up with the Kosher pieces before it was cooked then nullification occurred and all of them are considered Kosher even if they are then cooked together. Practically, many poskim are strict in this case since the taste of the forbidden piece mixture reawakens the nullified prohibition (Chozer Vneer).
- Awareness isn't necessary for the principle of Kol Dparish. That is, if an item is removed from a mixture and considered Kosher based on the majority of the mixture which it came from, it is Kosher even if the person wasn't aware of this until the situation became more complicated. Some poskim disagree and require awareness even for Kol Dparish to be effective.
- There is a discussion if the awareness of the nullification of someone other than the owner is effective.
Reawakening Nullified Ingredients
- If a forbidden food was nullified because there was sixty times it of permitted ingredients, and then more of the same type of forbidden food fell in, the entire mixture is forbidden unless the combined amount of forbidden food is nullified. This is based on the principle that even forbidden food which was nullified can be reawakened when more forbidden food is added.
What is Included in the Measurement
How the permitted items are measured
- When measuring the food in a pot to see if it nullified the forbidden ingredients we consider the gravy, scraps of meat, and large pieces of meat. Many poskim hold that dry bones, whether from a permitted or forbidden source, are also counted for nullification. However, the marrow of the bones from a forbidden source is also forbidden. Some poskim argue that bones from a forbidden source can't be counted towards nullification.
- The width of the pot doesn't count towards nullification. 
- We measure the mixture according to the size of the items when they come before the rabbi.
How the forbidden item is measured
Once It is Forbidden
- Once a solid food becomes forbidden by a transfer of taste it can never revert to becoming permitted again. That is, even if it is later cooked with sixty times its measure and is nullified, that piece remains forbidden.
- Once a food becomes forbidden by a transfer of taste in order to nullify it when it is part of a mixture, according to Ashkenazim, one needs to measure sixty times the entire volume of that food. This concept is known as Chaticha Naaseh Nevelah or Chanan. Sephardim only hold of this concept by meat and milk but for other prohibitions one only ever needs to nullify the volume of the original prohibition.
- Chanan only applies if one piece became forbidden before the rest of the mixture. That can happen if one piece was completely out of the gravy and something forbidden fell upon it (Chutz Mrotev). Another method of chanan is where two pieces are connected such as fat and an inner organ or the heart and meat nearby (Isur Davuk).
Unsure if there is Sixty
- If the food is before us, one must measure it to figure out whether the forbidden item was nullified. Even if it is impossible to measure as long as the forbidden mixture is in front of us, one can't be lenient unless one knows that there was at least sixty times of forbidden taste compared to the permitted taste. 
- However, if some of the mixture under question was lost or spilled and it is no longer possible to measure whether there was 60 times the prohibited ingredient or not but certainly the majority is permitted, if the mixture is one of similar types it is permitted, however, if it is of dissimilar types it is forbidden. 
- If there is a mixture of chicken and milk and there's certainly majority of chicken and a minority of milk but it is unclear if there is 60 times the amount of chicken in comparison to the milk or vice versa, and it is currently impossible to measure the mixture because some of it fell or was lost, some poskim are lenient and some are strict. 
Foods for which nullification doesn’t work
- Items for which nullification is ineffective because it is significant can be nullified when it falls into one mixture and one of that mixture falls into a second mixture and then one of the second mixture falls into a third mixture.
- Spices which were forbidden in it of themselves, such as Orlah, are forbidden even if there's sixty times the amount of permitted food in the mixture.
Dvar Sheyesh Lo Matirin
- If the prohibited food will be permitted after a certain time (Hebrew דבר שיש לו מתירין; trans. dvar sheyesh lo matirin), nullification doesn’t work unless it is mixed with a different type of food (different in name) in which case Bitul BeShishim is effective. Therefore, Chadash grain can not be nullified. The reason that a food which is going to become permitted is not nullified is because since it is possible to avoid relying on nullification one should do so. Alternatively, since nullification requires a clash and an item which is going to become permitted is essentially like it is permitted there is no way for that item to be nullified.
- Tevel (produce of Israel from which Trumot and Maaserot have not been removed) can't be nullified in a like mixture since it is possible to fix by taking off the trumot and maaserot. It is however nullified when in a mixture of unlike ingredients.
- Produce of Israel from the Shemitta (Sabbatical year) can’t be nullified unless it is mixed with a different type of food (different in name) in which case Bitul BeShishim is effective. 
- Something which is forbidden to someone and for others would be considered permitted after a time according to some is considered dvar sheyesh lo matirin, while according to many isn't considered dvar sheyesh lo matirin for the person for whom it is forbidden. For example, if something was intentionally cooked on Shabbat and was mixed in another food it is a dispute whether that considered dvar sheyesh lo matirin.
- A majority that isn’t in front of us to ascertain (ruba dlayta kaman) is effective even for a dvar sheyesh lo matirin.
- Kol dparish is effective even for dvar sheyesh lo matirin.
- Something subject to a dispute whether it is forbidden or an unanswered question of the gemara is nullified and not subject to the rules of dvar sheyesh lo matirin.
- Something that had a previous presumption of being permitted (chezkat heter) is nullified and not subject to the rules of dvar shyesh lo matirin.
See the details of this topic here: Kashering_the_Kitchen_for_Pesach#Nullification
- Foods use to serve Avoda Zara can't be nullified.
- Wine poured to Avoda Zara can't be nullified.
Biryah (Complete Unit)
- A complete creature or limb isn't nullified even in a mixture of foods that have a dissimilar taste.
- There are four conditions for a prohibition to be considered a biryah: 1) It was a living creature, 2) It was forbidden from its creation, 3) It is complete, 4) It isn't called by its original name after it is cut.
- Therefore, the following are considered a biryah: bugs, non-kosher birds, Gid Hanashah, Even Min Hachay, and an egg with a chick inside. Whereas a prohibited plants, Nevelah, Terefa, or Chelev aren't a biryah.
- An egg with a blood spot isn't considered a biryah.
- If there is a doubt if a food is kosher but it is certainly a biryah it isn't nullified. However, if there is a doubt if something is a biryah it is nullified.
- If the biryah is broken or split it is nullified. Some say that it could be nullified even while one is chewing.
See Checking for Bugs for more practical aspects of biryah.
- A complete creature or limb, a piece of meat which is suitable to serve guests, items which are always sold by unit (eggs which are sold by the dozen), and a prominent item (that Chazal specified) can not be nullified.  According to Ashkenazim a piece of meat which would be suitable to serve guests after being cooked is not able to be nullified and according to Sephardim only a piece of meat which is suitable to serve guests as of now (meaning, that it is cooked) is not able to be nullified. 
- An egg nowadays is considered a dvar shebeminyan according to many poskim.
Chaticha Hareuy Lhitchabed
- A forbidden piece of meat or fish that is significant that can be used to honor a guest isn't nullified in any amount. This applies to any prohibited item even if it is only rabbinically forbidden.
- If there's a doubt if it can be used to honor a guest one can be lenient.
- This rule only applies if the piece of meat or fish is forbidden in it of itself but not if it only absorbed a taste of something forbidden. The only exception is meat and milk which if combined each piece is completely forbidden in it of itself.
- Meat that was a person wasn't watching and became forbidden because of Basar SheNitalem Min HaAyin is nullified in a majority.
- A piece of cheese can be significant and considered a chaticha hareuya lhitchabed.
- Cheese that was made with teref rennet is not a chaticha hareuya lhitchabed.
- Cheese that was made with teref milk is a chaticha hareuya lhitchabed.
- Cheese made with Kosher milk mixed with milk from a non-Kosher animal isn't a chaticha hareuya lhitchabed.
- Cheese made by a non-Jew is a chaticha hareuya lhitchabed.
- Animals are considered important and aren't nullified.
- Something that is used to solidify or give a food texture is considered a critical ingredient and isn't nullified.
- Tagatose in diet slurpees is nullified. Therefore, some poskim would allow eating it with meat. Yet, others hold that the slurpee is dairy and as such the kashrut organizations mark it as dairy (see Star-K on Diet Pepsi).
- It's forbidden to intentionally mix forbidden food into permissible food so that it should become nullified. This rabbinic prohibition is called ein mevatlin isur lechatchila (Heb. אין מבטלין איסור לכתחלה; lit. "It is forbidden to initially nullify a prohibited item").
- If one did so intentionally, the food is forbidden for the person who did the nullification and his family as well as the person on whose behalf it was done and his family. If the person on whose behalf it was done didn't know about it, it is permitted for him.
- Others, however, may benefit from the mixture if it wasn't done specifically for their sake. 
- If one did so unintentionally, because one thought that it was permitted to do so, or because he forgot that the food was forbidden, the nullification is valid and the food is permitted.
- If a forbidden ingredient falls into kosher food one may not increase the ratio of kosher food to non-kosher in order to nullify the non-kosher. 
- A mixture which was permitted because of nullification of majority and one wishes to cook it together which would make it forbidden, one may intentionally add more permitted ingredients so that there would be 60 times the forbidden ingredient before one cooks it and the cooked mixture would be permitted. 
- Some say that if a rabbinically forbidden item fell into a mixture it is permitted to add more permitted ingredients in order to create nullification. Ashkanzim are stringent not to do so but in a case of a major loss a rabbi should be consulted.
- Therefore, a person should be careful never to try to use nullification without asking a qualified rabbi.
- A person may not ask a non-Jew to perform nullification for him. After the fact some hold it is forbidden and some disagree.
- Some say that it is forbidden to buy a product which was made with nullification if one can alternatively buy a product which doesn't use nullification. Others say that this is permitted. 
- If a pot absorbed a tiny amount of forbidden taste and it will always be used for sixty times that amount, it is permitted to use that pot after 24 hours have passed without having it go through a Koshering process. However, if the pot is sometimes used for a small amount of food and the absorbed taste wouldn't be nullified in sixty, it is forbidden to use that pot without Koshering even if one uses with an amount that would actually nullify the absorbed taste. 
- Some rishonim hold that it is permissible to nullify something prohibited if one doesn't intend to nullify it.
Noten Taam Lifgam
- If the taste of a forbidden food negatively impacts a mixture that it fell into the mixture is permitted.
- For example, bugs that fell into a food and were removed the food is permitted since the taste imparted by the bugs is negative.
- Meat in oil is considered by some to be contributing a negative taste and if the meat is forbidden and its taste gets mixed into the oil it is permitted, while others disagree.
- Meat in honey according to many poskim is considered to impart a positive taste.
- Sephardim hold that Chametz is permitted with the laws of Noten Taam Lifgam. Ashkenazim are strict.
- In order to strain raw honey from the bee parts it needs to be heated up. Even though the heating up cooks the parts of bees in the honey it remains kosher since the taste from the bee parts is noten taam lifgam.
- Food which imparts a taste which is neither positive or negative for the mixture is forbidden unless it is nullified by 60.
Inedible Forbidden Foods (Nifsal Machila)
- A forbidden food which spoiled and became inedible is biblically permitted but rabbinically forbidden.
- If someone eats forbidden foods that are made completely inedible it is nonetheless a rabbinic prohibition. The rabbinic is classically known as achshevey (Hebrew: אחשביה, lit. he made it important) it is considered as though he considered it edible since he intentionally eating it.
- Achshevey doesn't apply to a mixture.
- Achshevey doesn't apply to medicines.
- Achshevey doesn't apply if it isn't intentional to eat the forbidden food that is inedible.
Absorbed Taste in Utensils
- If food was cooked in a pot which was previously used for forbidden food within the same day, the food is forbidden unless the volume of the food is sixty times greater than the volume of the pot. Similarly, if a hot food was mixed with a utensil which absorbed forbidden flavors, the food is forbidden unless the volume of the food is sixty times greater than the volume of the part of the utensil which entered into the food. 
Chanan in Keilim
- If a meat spoon was last used for meat more than 24 hours earlier, then is used for milk that day, and is again used for meat that day, the spoon is considered to have only absorbed up to the volume of the milk that it was used for that day. Some are strict to assume that the spoon absorbed up to the full volume of the spoon if it is made of earthenware. 
- If a meat spoon was last used for meat with 24 hours, then is used for milk that day, and is again used for meat that day, the spoon is considered to have only absorbed up to the full volume of the spoon. Some are lenient in a case of great loss and the spoon isn’t made of earthenware.
Pots used for Non-Kosher Dvar Pogem
- If kosher food was cooked with non-kosher but the non-kosher ingredient makes the mixture taste worse, the food is permitted but the pot and spoon used for that cooking needs to koshered.
- If kosher food was cooked with non-kosher but the non-kosher ingredient makes the mixture taste worse, the spoon used to mix that food while it was on the fire would need to be koshered, however, if that spoon was then used to stir another pot that other food would be kosher and the second pot wouldn't need to be koshered.
Eino Ben Yomo Pots
- If a forbidden mixture was cooked in a pot and was used after 24 hours passed, the food is kosher but the pot needs to be koshered.
- One may not use a forbidden pot intentionally but if one did so according to many poskim the food is nonetheless permitted.
- An earthenware vessel that absorbed something non-kosher can't be used even after 24 hours.
- If a person used an eino ben yomo meat pot for dairy the food is permitted and the pot needs to be kashered but it can be koshered with hagalah even if it was used on the fire. The same is true of a dairy pot for meat.
Stam Kelim Einam Bnei Yoman
- Food cooked in a pot that wasn't used within 24 hours even if the pot wasn't kosher the food is kosher after the fact.
- If someone doesn't know if a pot was used within 24 hours after the fact the food is permitted since it is possible to assume that it wasn't used within 24 hours.
- Some say that it isn't necessary even to inquire if the pots were used within 24 hours if it would embarrassing to ask.
- An item which is found that separated from a majority but its status is unclear is considered to be like the status of the majority from which it came from.
- For example, if a piece of meat is found in a community with 10 stores, 9 of which are kosher, and 1 is non-kosher that piece is considered kosher since it is judged by the majority of stores. There is a large dispute regarding whether we judge the majority by the amount of stores or by the overall quantity of meat being sold at each store and if the majority of the total meat sold in all ten stores is kosher the piece is kosher.
- See above if kol dparish applies to dvar sheyesh lo matirin.
- See above if kol dparish requires awareness of the prohibition.
- This principle is based on the pasuk "אחרי רבים להטת" (Shemot 23:2) meaning that one should follow the majority.
- Rashi chullin 98b
- Tosfot Chullin 98b s.v. Rava based on the Gemara Pesachim 44b which derives from the pasuk that bread with the taste of wine is biblically forbidden to a nazir.
- Badei Hashulchan 98:12 rules that nullification depends on the volume and not weight.
- Shulchan Aruch Y.D. 98:1-2, Badei Hashulchan 98:1. Bet Yosef 98:1 argues that Rashi would agree that if there's a proportion of a kezayit within a pras of the mixture it is biblically forbidden. Even though Rashi Avoda Zara 67b isn't clear that he agrees, the Ritva Avoda Zara 67a s.v. amar agrees with the Bet Yosef. See Pesachim 44a as well that kezayit kdei achilat pras is biblical according to everyone. Minchat Cohen 1:2 and Lechem Mishna Machalot Asurot 15:2 ask on Bet Yosef that Rashi Avoda Zara doesn't sound like he agrees. For answers for the Bet Yosef see Rabbi Akiva Eiger and Chavot Daat.
- The Rash Tavul Yom 2:3 writes that Kezayit Bkdei Achilat Pras is biblical even regarding min bmino. However, Maharam Chalavah Pesachim 44a explicitly disagrees. Tosfot Pesachim 44a and Ritva A"Z 67b s.v. amar also disagrees with the Rash. See Baal Hameor Pesachim 44a who seems to agree with the Rash.
- Gemara Chullin 108b, Rama 98:4
- Rama 98:4. See Badei Hashulchan 98:61 who explains why we don’t assume that the forbidden taste reawakens when the forbidden item falls in again.
- Shulchan Aruch Y.D. 98:6
- Rama 98:8. See Badei Hashulchan 98:84 whether this is biblically forbidden or rabbinically. The Taz holds that this only applies to spices or sharp foods but not everything that has a strong taste. See Badei Hashulchan 98:87 for a variant opinion.
- Rama 98:4 writes that if the forbidden item is recognizable it must be removed. He adds that even if the forbidden ingredient has the potential to become recognizable it needs to be removed. For example, if forbidden fat fell into a mixture, one should pour in water to cause the fat to rise and then remove it. Shach 98:16 and Kaf HaChaim 98:57 note that even if the forbidden fat is removed by having it rise to the top still the food is forbidden unless the permitted ingredients are sixty times the forbidden fats. Kaf HaChaim 98:59 quotes a dispute between the Kereti and Pri Megadim whether one needs to do this procedure if it’ll ruin the food and concludes that for a major loss one can be lenient.
- Rama 98:4
- Badei Hashulchan 98:55
- *The gemara Zevachim 78b explains that a mixture of like ingredients is nullified by majority on a biblical level and nullified by one in sixty on a rabbinic level, whereas mixtures of different types are only nullified even on a biblical level if there’s one in sixty. Why do you need 60 needs to nullified the forbidden food in a mixture of like types? The Rosh (Chullin 7:37) explains that it is a particular prohibition to avoid any confusion between these two categories. However, the Rambam (Machalot Asurot 15:4-5) understands that this rabbinic prohibition was such that a forbidden food is never nullified until it is dispersed in such a great quantity such as one in sixty that it is completely lost. The Badei Hashulchan 98:13 cites this dispute.
- The Rama 98:2 holds that the distinguishing factor between like mixtures and mixtures of different types depends on the type of food and its name. However, the Shach 98:6 argues that the distinguishing factor is the taste of the foods. The Badei Hashulchan 98:19 writes that we hold like the Shach.
- Shach 98:1 and Taz 98:1, Badei Hashulchan 98:2
- Badei Hashulchan 98:14
- The Gemara Chullin 98b assumes that it is possible to nullify a forbidden item in a mixture of permitted ones. Rashi s.v. de’mdeoritta explains that this is based on the pasuk Shemot 23:2 which says that we follow majority. Shach YD 109:6 agrees. See Gemara Chullin 11a which employs that pasuk for the rule of following majority for items that leave a mixture. See also the Shaarei Yosher 3:4 regarding the difference between these concepts. The concept of nullification with a majority is codified by the Tur and Shulchan Aruch YD 109:1.
- Rambam (Maachalot Asurot 15:4) and Raavad (cited by Ran Chullin 36a s.v. garsinan) hold that even for a dry mixture nullification doesn’t happen with a majority but rather only if there is sixty times the amount of the forbidden item is the mixture permitted. However, the Tosfot (Zevachim 72a), Sefer HaTrumah (Siman 50 s.v. hilkach), Smag (Lavin 140-1), and Rashba (Torat HaBayit 17a) hold that it is permitted even on a rabbinic level with a simple majority. This dispute is discussed in the Bet Yosef YD 109:1. Tur and Shulchan Aruch YD 109:1 hold like the Tosfot.
- The Pitchei Yeshuva YD 109:1 cites a dispute between the Pri Chadash and Minchat Yakov whether one needs a simple majority of 51% or one needs a ratio of 1:2, or 66.7% of permitted food in the mixture in order to have nullification. He advises being stringent. Kaf Hachaim 109:9 agrees.
- The Rosh (Chullin 7:37) writes that bitul makes the asur item turn into heter and one person can eat all 3 pieces of the mixture at once. However, the Rashba in Torat HaBayit (BeDini HaTaarovot p. 17) argues that you can’t eat them at once. When you eat each piece there’s another logic to allow that piece since it could be that the forbidden item was left in the rest of the mixture. Even upon eating the last piece it could be argued that that piece is permitted and the forbidden piece was already eaten. Shulchan Aruch YD 109:1 agrees with the Rashba. The Pri Megadim M”Z 109:1 writes that the Rashba agrees with the Rosh on a biblical level.
- Interestingly, Shach 109:7 adds that it is permitted to eat two pieces at once and then the last one or vice versa as long as one doesn't eat all three at once. However, the Kaf HaChaim 109:20 and Aruch Hashulchan 109:20 argue that it is forbidden because taking two at once is effectively eating the majority with the forbidden item in it. Additionally, the Shach 109:12 writes that it is equally permitted to cook them in two pots.
- Tosfot Rid (b”b 31b s.v. shtei) in fact says it can’t be eaten by one person and doing so would be biblically forbidden. Smag (lavin 141 s.v. shaninu) and Tosfot Chullin 100a s.v. biryah says that two people should eat it.
- Rashi Avoda Zara (74a s.v. tarti) holds that in order to allow the mixture one of the pieces needs to be thrown out or thrown to the dogs. However, the Rosh (Avoda Zara 5:30) argues that the only reason that the Mishna Orlah 2:1 one would remove the amount of trumah added to a mixture which nullified the trumah is in order not to steal from the kohanim. Hagahot Sharei Dura (39:6) agrees. The Rama YD 109:1 writes that there is a stringency to be concerned for Rashi and throw out one of the pieces.
- Shach YD 109:7 and Pri Chadash 98 s.v. veleinyan assume that differences in taste is critical to consider two foods to be two types unlike the Bach who considers foods to be different if they have a different identification or classification. Shach YD 98:6 argues again at length with the Rama that the critical factor is taste and not identification.
- The Tur YD 109:1 postulates that there’s no difference whether the pieces in the mixture are of the same types of different types. However, he also cites the Sefer HaTrumah who says that if there’s different types there is a need of sixty times the forbidden amount in order to have nullification. The Bet Yosef YD 109:1 cites the Ran (Chullin 36b, end of Perek Gid HaNasheh) who says that it is forbidden unless there is sixty times the amount of forbidden food in the mixture. His reasoning is that since if the mixture were to be cooked together the need for having sixty for nullification would be biblical, there is a rabbinic need for sixty for nullification even though it is a dry mixture. The Hagahot Shaarei Dura 39 holds that this is biblically forbidden, while the Iser Veheter 26:11 holds it is only rabbinically forbidden. The Shach 109:10 cites the Maharshal, Torat Chatat 39:4, Ran (Chullin 36b), and Rashba (Chullin 97b s.v. ubekedeirah) who side with the Iser Veheter. Shulchan Aruch YD 109:1 (according to the Shach 109:2) and Rama ad loc. hold like the Sefer HaTrumah and require sixty for nullification of a dry mixture when there’s two different types in the mixture.
- The Shach 109:9 concludes based on the Ran that if there’s a dry mixture of different types with only a rabbinic prohibition mixed in it is nullified with a majority. The Rama 109:1 seems to equate the cases whether it was a rabbinically prohibited or biblically prohibited item that it should require sixty times for nullification of different types. The Gra 109:8 agrees.
- The Rashba (Torat HaBayit 17a, responsa 1:272) holds that once the mixture is cooked together it is forbidden even though it is a mixture of one type since once it is cooked together the entire mixture shares the taste of the forbidden food. This is also the opinion of the Ran (Chullin 36a s.v. garsinan). The Rosh (Chullin 7:37) and Smak (Siman 214) argue that it is permitted even if it was cooked together. Shulchan Aruch YD 109:2 rules like the Rashba, while the Rama adds that in a case of a major loss one may rely on the Rosh.
- Shulchan Aruch YD 109:1, The Laws of Kashrus (Rabbi Binyamin Forst; pg 54-6)
- Halachically Speaking vol 4 issue 18
- Chinuch Bet Yehuda 80 cited by Pitchei Teshuva YD 109:2
- Chazon Ish YD 37:20. See Rashba 1:272 who implies that majority of volume is all that is necessary.
- Shulchan Aruch 104:1
- Shach 109:4
- Shulchan Aruch 104:1. Rama limits it to a sheretz but Taz 104:2 argues. Ran Avoda Zara 32b s.v. hahu agrees with Tosfot that it is relevant to all prohibitions. He asks two questions on Rashi. 1) Why doesn't chatzi shiur make it asur for all prohibitions? 2) Why couldn't they strain out the solids?
- Shulchan Aruch and Rama 109:1-2, The Laws of Kashrus (Rabbi Binyamin Forst; pg 58-61)
- According to Rabbi Yehuda (Menachot 22a) a mixture of items of a similar type aren't nullified, however, according to the Rabbis it is. Rashi (Chullin 109a s.v. VeTu) holds like Rabbi Yehuda. Tosfot (Chullin 97a s.v. amar rava), however, argues with Rashi and rules that we hold like the Rabbis. Ran (Chullin 34b), Rosh (Avoda Zara 5:29), and Rambam (Maachalot Asurot 15:6) agree with Tosfot. Tur and Shulchan Aruch YD 98:2 hold like the Rabbis that a mixture of similar items is nullified.
- Rava in gemara Chullin 97a states that one can rely on the testimony of a non-Jewish chef that a mixture of meat and a bit of milk doesn't have any dairy taste in it to permit it to a Jew. Concludes the gemara, if there no chef around or it is a mixture of similar items and it is impossible to taste the forbidden item specifically, one needs nullification of 60. (a) Rashi (Chullin 98a s.v. beshishim) implies that even if there's no taste of the forbidden ingredient still the mixture is forbidden unless there is also nullification of 60. (b) Similarly, the Ramban Chullin 98a s.v. kol holds that if the forbidden food dissolved into the permitted food it is nullified with 60 and not the taste of a chef. Yet, if the forbidden food was removed from the mixture but its taste remains it is nullified with the taste of a chef even if that's less than 60. (c) However, the Tosfot Chullin 99a s.v. elah and Rosh (Chullin 7:29) argue that if the non-Jew doesn't taste the forbidden ingredient it is permitted even if there isn't nullification of 60. (d) The Bet Yosef YD 98:1 understands that the Rambam (Machalot Asurot 15) thinks if there's an option to ask a non-Jewish chef one should and if he says that there's a forbidden taste, it is forbidden even if there's nullification of 60 and if he says that there's no forbidden taste it is permitted even if there's not nullification of 60.
- Shulchan Aruch YD 98:1 holds like the Rambam. However, the Rama 98:1 based on the Agur writes that the minhag Ashkenazim is not to rely on a non-Jew to taste for a forbidden taste and just always use nullification of 60. The Kaf HaChaim 98:2 records that the Sephardic minhag was also to always use nullification of 60.
- While the Shach 109:5 writes that we can rely on the taste of a Jew when it is permitted for the Jew to taste it, the Kaf HaChaim 109:12 quotes the Chavot Daat 109:2 who disagrees.
- Pitchei Teshuva 109:2 writes that when evaluating nullification volume is measured and not weight. Kaf HaChaim 109:5 agrees.
- Shulchan Aruch YD 109:2 based on the Rashba (Torat HaBayit 17a)
- Rama 109:2 based on the Rosh, however, Kaf HaChaim 109:40 writes that Sephardim don’t hold of this leniency.
- Based on the Gemara Chullin 97b, Rashba in Torat HaBayit holds that whenever a forbidden item is cooked into a mixture and then is removed, the amount of flavor that emanated from it could be as large as the actual item itself. He holds this regarding all types of prohibited food even rabbinic prohibitions. This is opposition to the opinion of the Orchot Chaim (Maachalot Asurot no. 13) and Raavad (Tamim Deyim no. 7) who distinguish between different types of prohibitions. Shulchan Aruch YD 98:4 rules like the Rashba. Shach 98:10 and Kaf HaChaim 98:44 adds the stipulation that applies even to rabbinic prohibitions.
- While the Rambam (Maachalot Asurot 15:17) holds that all rabbinic prohibitions are nullified with fifty nine times the amount of the forbidden ingredients, the Bet Yosef 98:8 writes that the majority of poskim disagree and Rama YD 98:8 writes that sixty times is necessary. Kaf HaChaim 98:73 agrees. The Gemara Chullin 98a states that if a forbidden food is less than the requisite size of the prohibited food (shiur), it still requires sixty times for nullification. This is codified by Shulchan Aruch YD 98:6.
- The Shulchan Aruch YD 98:2 is lenient even if there's a doubt if there's sixty but the Shach 98:6 disagrees because it is a biblical issue so one couldn't be lenient in a case of doubt. However, if there's a certain sixty that is permitted according to everyone. Pri Megadim M"Z 98:3 clarifies this as well.
- The Pri Megadim (Shaar Hataarovet 3:1 s.v. vnistapakti) has a doubt about a case in which there's 1/2 a piece of nevelah meat, 1/2 a piece of kosher meat, and 30 pieces of vegetables. On the one hand, one will taste the taste of meat in the 30 pieces of vegetables and since the taste of meat is comprised of both the kosher and non-Kosher it is forbidden. Yet, the Kereti assumes that this is permitted since the taste of the non-Kosher meat dispersed into sixty times its volume of Kosher ingredients. The Pri Megadim proves from the Taz OC 318:15 that it is forbidden. In OC M"Z 318:15 he points out that the Rama and Eliya Rabba seem to be lenient on this question as long as the forbidden ingredient wasn't sufficient on its own to give a taste because of Zeh Vezeh Gorem. Likutei Megadim quotes the Maharam Shik YD 114 who says that it is permitted since there's no way that something permitted can cause Chozer Vneer from the Gemara Bechorot 20a. But there would be less than 60 it would be forbidden biblically since the meat is tasted. He also quotes the Bet Yehuda 98:2 s.v. nireh who is lenient since the taste of the forbidden ingredient is masked by the permitted ingredient. See Rambam (Machalot Asurot 15:22) who also implies it is permitted.
- Rambam Machalot Assurot 15:13-4
- Mishna Trumot 5:8, Rosh Chullin 7:37
- The Shach 109:12 writes that without an awareness of the mixture biblically there isn't nullification. Pri Chadash 109:10 agrees. Chachmat Adam 51:18 and Kaf Hachaim 109:45 agree with the Shach and disproves the Minchat Yaakov.
- Minchat Yaakov 39:18
- Rama 109:2
- Shulchan Aruch YD 109:2 is strict. Kaf Hachaim 109:40 agrees even if there's great loss. Rama is lenient in cases of great loss.
- Binyamin Zeev (Kuntres Acharon n. 14), Rav Poalim YD 1:23 s.v. Vachar, Chazon Ish 37:20. Minchat Pittim (Rav Meir Arik YD 8) writes that Kol Dparish doesn't require awareness for it to be effective. He proves it from the Ran Chullin 33b s.v. amar. Darkei Teshuva 110:59 cites the Minchat Pittim.
- Binat Adam Bet Hakavuah n. 13
- Yerushalmi Orlah 2:1 seems to in doubt about awareness of a friend if that's effective. Darkei Teshuva 109:65 quotes the Levushei Sharad 109:25 who holds that nullification is only effective if the owner knew. He also quotes Yad Elimelech 5 who holds that for a rabbinic prohibition awareness of someone else is effective.
- Rama 99:6 rules like the Rosh who says that even if all the ingredients are dry, even if they're all of the same type, and even if one knew about the nullification before the second forbidden food fell in, still the old forbidden food is reawakened and forbidden. The Shach 99:21 argues that if there's no concern of taste being transferred such as where the ingredients are dry, of the same type, and one knew about the nullification before the next piece of forbidden food fell in one can be lenient to assume that the old forbidden food is reawakened. Kaf HaChaim 99:70 and The Laws of Kashrut (p. 68) follow the Rama against the Shach.
- Shulchan Aruch YD 99:4
- Shulchan Aruch 99:1 rules like the Rashba (Torat HaBayit 6a) that even the forbidden bones count towards nullification, but the Rama cites the Or Zaruah who holds that the forbidden bones can't be considered towards nullification and adds that in cases of loss one can rely on the Rashba. Kaf HaChaim 99:11 writes that Sephardim primarily follow Shulchan Aruch here. The Shach 99:1 and Kaf HaChaim 99:2 are strict regarding moist bones from a forbidden source to include them in the measurement of the forbidden ingredients.
- Tur and Shulchan Aruch YD 99:1
- Shulchan Aruch YD 99:4
- The Rashba holds that once a piece of food becomes forbidden it can never revert to become permitted. Tur 106:1 disagrees. Shulchan Aruch Y.D. 106:1 accepts the Rashba. However, in Y.D. 92:4 the Shulchan Aruch uses the language of the Tur. Taz 92:10 and Gra 92:16 point out this contradiction but side with the Rashba. Shach 92:11 reads the Shulchan Aruch 92:4 in light of 106:1. Therefore, the conclusion of the poskim is like the Rashba (Horah Brurah 92:32).
- Gemara Chullin 108b, Rama 92:4. Taz 92:11 points out that many poskim hold that this applies even to a rabbinic prohibition. Badei Hashulchan 92:64 agrees. Taz 87:2 implies the same.
- Shulchan Aruch Y.D. 92:4, Horah Brurah 92:34
- Rama 92:4
- Orchot Chaim (Machalot Asurot n. 14 s.v. hareviyi) quoting the Rabbenu Peretz, Bet Yosef 98:2
- Shulchan Aruch YD 98:3 writes that only if a mixture is before us one must measure it, however, if it was spilled and one doesn't know how much was in the mixture and whether that was sufficient to nullify the forbidden taste that's considered a doubt. The Taz 98:6 quotes the Mordechai who explains that if a fool can't measure it but it is possible for other people to measure that's not considered a doubt since it is possible to ask someone else to measure it. However, if no one in the generation knows how to measure it that's considered a valid doubt. The Shach 98:9 similarly quotes the Mordechai but also quotes the Ran who says that as long as the mixture is before us it isn't considered as though there's a doubt if there's nullification as the Rabbis made an enactment without distinctions. The Kaf HaChaim 98:43 cites the Shach and notes that it seems that the Taz's leniency, that if no one knows how to measure it, it is considered a doubt even if the mixture is before us, is against the Ran.
- As an outgrowth of this discussion, if a non-Jew or child added forbidden food to a pot and one can't know how much forbidden ingredients were added, the Pitchei Teshuva 98:8 quotes the Emunat Shmuel who believes that it is considered like the case of the food spilling or getting lost since it is nearly impossible to figure out the measurement. Nonetheless, the Emunat Shmuel writes that his logic was speculative and not definitive for a ruling. The Pri Chadash 98:9 agrees with the Emunat Shmuel even as definitive ruling. Chachmat Adam 51:13 and Badei HaShulchan 98:17 hold like the Pri Chadash that the addition of forbidden food by a child or non-Jew in a case where it is impossible to measure the amount of forbidden food that was added is considered a valid doubt.
- Rashba (Torat HaBayit 11b), Tur and Shulchan Aruch YD 98:2. The logic of the Rashba is that he follows Rabbenu Tam (Tosfot Chullin 98b s.v. rava) who says that in a liquid mixture of different types the need for nullification is biblical and since there is a doubt about a biblical prohibition one should be strict. The general principle is that when dealing with doubts about a biblical prohibition one should be strict. However, he states a mixture of like types biblically is nullified with majority and only rabbinically needs nullification of 60 and so if one is in doubt one can be lenient. This is also the opinion of the Rosh (as cited by the Tur 98:3). It is noteworthy to mention that the opinion of Rashi (Chullin 98b s.v. letaam) and the Rambam (Machalot Asurot 15:2-3, as understood by the Bet Yosef YD 98:2; responsa of the Rambam Pear Hadur 65) is that even a liquid mixture of different types is biblically nullified with majority only needs nullification of 60 rabbinically. Shulchan Aruch YD 98:2 follows the Rashba.
- According to the Shach 98:7 it is permitted based on the logic of the Rashba that we should say since there is only a rabbinic prohibition and there's certainly nullification on a biblical level we can be lenient. However, the Taz 98:5 argue that it is forbidden since we treat chicken and milk like meat and milk for all intents and purposes even though it is rabbinic. Pitchei Teshuva 98:6 cites the Emunat Shmuel and Pri Chadash as agreeing.
- Shulchan Aruch YD 110:8
- Zevachim 74a cites a dispute between rav and shmuel whether two rov’s are sufficient to permit a prohibition for which bitul is ineffective. Rav is lenient, while Shmuel is strict for Avoda Zara. Rambam Machalot Asurot 8:11 follows Rav unlike the Raavad who follows Shmuel.
- Rambam seemingly contradicts himself whether a second or third mixture is necessary. Kesef Mishna Avoda Zara 7:10 answers for the Rambam that the nullification of rimonim of trumah might be taken lightly so we're stricter. Alternatively it is like a dvar sheyesh lo matirin since there's something that can be done to solve the issue if they were broken. However, the Gra answers that the Rambam thinks that you need three tarovot whenever we’re discussing something that isn’t batel since the rabbis treated the first tarovet as though it was certainly forbidden. Then you need another two mixtures to be lenient. However, the reason that avoda zara isn’t nullified is because safek avoda zara is forbidden and as such a double rov is sufficient.
- Rashba holds that they’re permitted in the second mixture Bet Yosef posts that even according to the Rashba one couldn’t eat all of the pieces of the second mixture simultaneously because of his opinion cited in S”A 109:1.
- Rashi holds that the second mixture is forbidden unless something of it falls out into another mixture. That is because Rashi a”z 74a generally holds that bitul requires something to be removed for the mixture. Birchat Hazevach explains rashi similarly. However, Chok Natan explains that Rashi holds that unless there’s another mixture it is a problem since the third mixture creates another safek.
- Tosfot posits that really you can be lenient with the second mixture you just can’t eat the entire thing. However, if there are is a third mixture you can benefit from all of them.
- Rashi kitvei yad writes that the second mixture is completely permitted.
- Shulchan Aruch YD 110:8 rules that a third mixture is necessary like Rambam Machalot Asurot 8:11. Shach 110:50 writes that in a case of loss one can follow Tosfot.
- Rama YD 98:8. Shach 98:29 quotes the Iser Veheter who says that this is only rabbinic. Taz 98:11 holds that the idea of the Rama that something added for taste can't be nullified only applies to sharp tasting foods such as spices. Taz also states that if the spices are only forbidden because of the mixture, such as meat and milk, they can be nullified and only if they are forbidden in it of itself can't they be nullified.
- Gemara Beitzah 3b, Rambam (Hilchot Maachalot Asurot 15:10), Shulchan Aruch Y.D. 102:1
- The Laws of Kashrus (Rabbi Binaymin Forst; pg 62)
- Rashi Beitzah 3b s.v. afilu. Rabbenu Dovid Peachim 30a s.v. viy lav explains that really the rabbis wanted to make a gezerah to forbid relying upon bitul altogether, but in order not to cause a major loss to Jews in many situations they did not impose such a gezerah. However, since for a dvar sheyesh lo matirin it is easy to be stringent and not rely on bitul one must do so.
- Ran Nedarim 52a. See further in Ran responsa 59 regarding nullification of heter in heter.
- Gemara Nedarim 58a, Rashba Beitzah 3b s.v. ha, Rambam Machalot Asurot 15:6
- Rambam Machalot Assurot 15:8. See Encyclopedia Talmudit s.v. Bitul Isurim which quotes a machloket rishonim if the rule that shemitta produce isn't nullified in any amount whether it applies only before the time of biyur (Ran Nedarim 58a, Raavad Machalot Asurot 15:6, Shemita 7:3), only after the time of biyur (Rash and Rav Shemitta 7:7) or both (Rambam). The Ran explains that Shemitta produce isn't nullified because it could all be eaten with Shemitta holiness and is a dvar sheyesh lo matirin.
- The Rama 102:4 quotes Rabbenu Yerucham that it isn't considered dvar sheyesh lo matirin if for someone else it is permitted after a time. However, the Magen Avraham 318:2 argues since it is permitted for someone else after a time and it is like bikkurim. However, the Chavot Daat 102 disputes that point. Mishna Brurah 318:5 and Badei Hashulchan 102:54 cite the dispute without any resolution.
- Ran Beitzah 3b s.v. vdavka, Rabbenu Peretz Pesachim 7a s.v. bhar, Ritva Pesachim 7a s.v. umi, Rabbenu Dovid Pesachim 9b, Tzlach Pesachim 7a s.v. ulbatar, Peni Yehoshua Pesachim 7a s.v. btosfot lifnei, Mordechai Beitzah n. 651. See Rashba (Avodat Hakodesh Bet Moed 5:4:58) who is strict on a ruba dlayta kaman for a dvar sheyesh lo matirin. Though it seems there that it is only a minhag, Maggid Mishna Yom Tov 4:24 quotes the Rashba as holding it is asur. See however, Rashba Beitzah 7b s.v. ki who sounds like he’s lenient. Magen Avraham 513:3 is strict.
- Pitchei Teshuva YD 102:1, Tzlach Pesachim 7a s.v. ulbatar
- Gidulei Hekdesh 330:2 citing Pri Chadash, Rabbi Akiva Eiger (responsa 65 and hagahot YD 16), Shagat Aryeh 90, and Pri Megadim (Intro to Yom Tov 2:1:27) unlike the Taz 497:9. Gidulei Hekdesh supports the Taz fom Rashi Eruvin 39b s.v. lo. Yabia Omer EH 6:2 follows Pri Chadash and quotes Maharsham 2:156 who prove from Tosfot Yoma 47b s.v. hadar and Rabbi Akiva Eiger 65 s.v. v'af who proves from Ran Nedarim 47b like Pri Chadash.
- Gidulei Hekdesh 330:2 quoting Nodeh Beyehuda EH 38. He supports it from Eruvin 56a.
- Shulchan Aruch O.C. 447:1
- Shulchan Aruch YD 140
- Rambam Machalot Asurot 15:6
- Darkei Moshe 100 cites the Isur Veheter who says that biryah is permitted if it is mixed with ingredients of dissimilar tastes. Shulchan Aruch 100:3 rules like the Rashba that biryah isn't nullified.
- Macot 16a, Rosh Chullin 7:33, Shulchan Aruch YD 100:1
- Rashi Chullin 102b s.v. tameh
- Gemara Macot 16b, Tur 101:6 and Shulchan Aruch YD 100:1
- Rosh Chullin 7:33, Shulchan Aruch YD 100:1
- Shulchan Aruch YD 100:1, Shach 100:4
- Shach 100:2
- Taz 100:1 writes that since biryah is only rabbinic it is considered permitted if there is a doubt if it is biryah. If it is a doubt if it is kosher it is considered non-kosher based on safek deoritta lchumra and then afterwards that question isn't revisited when considering it a biryah that isn't nullified (safek deoritta sh'nitgalgel lehiyot derabbanan).
- Chazon Ish YD 14(1):6 s.v. vshiur writes that even if a biryah is broken while it is being chewed it is nullified. Mechzeh Eliyahu 1:89 questions this.
- Shulchan Aruch YD 100, 101, Shulchan Aruch and Rama 110:1
- Shulchan Aruch and Rama 101:3, Taz 101:5
- Ohel Yakov Isur Vheter p. 505 quotes Rav Sheinberg and Rav Nevinsal that eggs today are considered a dvar shebeminyan since they are sold by number. However, Rav Reuven Feinstein holds that it isn't a dvar shebeminyan since they only sell in it as a dozen for convenience but that is merely a sign of its weight.
- Shulchan Aruch 101:1
- Rama 101:1
- Rama YD 101:1. Pri Megadim M"Z 101:2 asks how there could be a doubt if something is useful to honor a guest, it is ascertainable (see Shulchan Aruch YD 98:3). He quotes the Pri Toar 101:4 who answers that with respect to objective questions whether it is ascertainable it isn't a doubt but since this is a subjective question one could be in doubt.
- Shulchan Aruch 101:2
- Rabbi Akiva Eiger 101:1 based on Shach Klalei Safek Safeka 110:19 that there is no issue of Chaticha Hareuya Lhitchabed for meat that wasn't watched which is a chumra derabbanan and not like other derabbanan's.
- The Maharshal (Yam Shel Shlomo Kol Habasar 108 cited by Taz) writes that cheese isn’t a chaticha hareuya lhitchabed since a person can’t eat so much of it until he gets full. Also some people don’t like it at all. Therefore, it isn’t a chaticha hareuya lhitchabed. Taz 101:3 argues that cheese is a chaticha hareuya lhitchabed and it is evident in the Rashba (Torat Habayit 91a).
- Torat Chatat 40:2, Taz 101:3, Nekudat Hakesef 101:1. Even though the Torat Chatat thought that the Isur Vheter was strict in this case the Nekudat Hakesef points out that Isur Vheter didn’t say that. Also, even though the Taz accused the Bach of saying that it is a chaticha hareuya lhitchabed the Nekudat Hakesef argues that the Bach never said it.
- Nekudat Hakesef 101:1
- Taz 101:3 explains that since the non-Kosher milk doesn't congeal into cheese but is just stuck in pockets in the cheese though non-kosher milk isn't considered significant.
- The Isur Vheter 25:8 writes that cheese made by a goy is a chaticha hareuya lhitchabed since it was forbidden from the moment it was created. Rama in Torat Chatat 40:2 writes that if it is cheese made with kosher milk and teref rennet it isn’t a chaticha hareuya lhitchabed since it only absorbed the taste of something forbidden. Bach 101:2 argues with the Rama and concludes like the Isur Vheter that all cheese made by a non-Jew is a chaticha hareuya lhitchabed. However, the Nekudat Hakesef agrees with the Bach that any cheese made by a non-Jew is a chaticha hareuya lhitchabed.
- The Taz 101:3 distinguishes between when the cheese was made with hide of a nevelah that it is considered a chaticha hareuya lhitchabed since from the creation of the cheese it was forbidden and the cheese which was made by a non-Jew and there’s a concern that mixed in is non-kosher milk that it isn’t a chaticha hareuya lhitchabed.
- Zevachim 73a, Rambam Machalot Asurot 16:7, Shulchan Aruch YD 110:1
- Rambam Machalot Asurot 16:26
- Firstly, tagatose could be parve since it is a sugar processed from dairy (see [KosherVeyosher.com http://www.kosherveyosher.com/lactose-reb-elyashiv-teshuva.html] based on Rav Elyashiv in Kovetz Teshuvot 1:73). Secondly, the tagatose could be nullified in sixty since it is permitted (Shulchan Aruch YD 87:11). Rabbi Sholem Fishbane writes that after asking poskim there was a division if the slurpee was dairy even though the tagatose was nullified. He quotes Rav Gedalya Dov Schwartz as holding it was dairy. CRC prints this article as well.
- Gemara Beitzah 4a, Shulchan Aruch YD 99:5. The Raavad (Isur Mashehu ch. 2) considers this to be biblically forbidden, while the Ran (Chullin 35b) and Rashba (Torat HaBayit 31b) hold that it is derabbanan. See Bet Yosef Y"D 99, Shach 99:7, and Chachmat Adam 52:6
- The Yerushalmi Orlah 3:6 states that if a person did nullify a prohibited item, if done so intentionally it is forbidden if unintentionally it is permitted. This is echoed in the opinions of Rabbi Shimon and Rabbi Yose in Gittin 54b. The Rambam (Maachalot Asurot 15:25, according to the Bet Yosef 99:5), Rashba (Torat HaBayit 31b), and Tur 99:5 codify this as the halacha. Shulchan Aruch YD 99:5 concurs. The Rashba (Torat HaBayit 32a) writes that the food is forbidden for the person doing the nullification as well as the one for whom it was does on his behalf so that he doesn't benefit from his sinful actions. The Rashba cites the Rambam and Raavad in agreement with this idea. Shulchan Aruch YD 99:5 codifies this. Additionally, the Maharshal cited by the Taz 99:10 writes that anytime it is forbidden for the person it is also forbidden for his whole family. The Kaf HaChaim 99:45 agrees. See Kaf HaChaim 99:46 regarding the dispute whether the penalty against one who did nullification includes the pot as well.
- Taz 99:10, Kaf HaChaim 99:44
- Shulchan Aruch YD 99:5
- Shulchan Aruch YD 99:5 writes that if the nullification happened unintentionally the food is permitted. See previous footnote for his sources. The Taz 99:7 states that if a person thought it was permitted to do so, it is considered as though he was unintentional. Kaf HaChaim 99:38 and The Laws of Kashrut (p. 75) agree. The Kaf HaChaim 99:41 writes that if a person forgot that it was forbidden that too is considered unintentional.
- Shulchan Aruch Y"D 99:5
- Shulchan Aruch YD 109:2 based on the Raah. The Taz 109:3 and Shach 109:13 explain that the logic for this is that since the mixture is currently permitted it is permitted to add as much as one wishes even though it is preventing an forbidden item from prohibiting the mixture later upon cooking it.
- Shulchan Aruch YD 99:6 permits adding to a mixture with a rabbinically forbidden item in order to permit it with nullification. This is based on the Gemara Beitzah 4b. The Rama, however, argues that it is forbidden to do so. See Shulchan Aruch OC 677:4 who seems to forbid as well. Kaf HaChaim 99:68 writes that the Sephardi minhag is to follow Shulchan Aruch and allow nullification on derabbanan prohibitions by adding to the mixture. Pri Megadim Siftei Daat 99:17 writes that once a few barrels of chametz liquor made on Pesach was mixed with a barrel of liquor made afterwards since it was a major loss it was permitted to add more in order to create the nullification.
- The Laws of Kashrut (p. 75). See Pitchei Teshuva 99:5 regarding a person who asked an unqualified rabbi and he ruled incorrectly that it is considered intentional. See, however, Kaf HaChaim 99:39.
- Rashba Torat Habayit Haaruch 4:4 38b writes that it is forbidden to ask a non-Jew to cook in his teref pot that wasn’t used within 24 hours since it is considered bitul isur lechatchila. Rashba writes that it is forbidden even after the fact. Shulchan Aruch YD 103:5 and 122:6 quotes the Rashba but not the part that it makes it forbidden after the fact. Even though the Levushei Sarad and Chamudei Doniel say it is forbidden even after the fact like the Rashba, Igrot Moshe YD 2:41 argues that after the fact we are lenient.
- Kaf HaChaim 99:52 cites the Radvaz 3:547 who is strict against the Erech HaShulchan YD 99:8 who is lenient. The Badei HaShulchan 99:38 and Yabia Omer YD 7:7 are lenient.
- Radvaz 3:547 writes that it is forbidden to buy a product from a non-Jew if there’s something in it that was forbidden but was nullified. He admits though that it is permitted if it was just cooked in a pot that wasn’t used within 24 hours. He explains that it isn’t likely one is going to ask a non-Jew to cook in such a pot since it doesn't impart a good flavor. Yet it is a problem to buy the food which had non-Kosher mixed in since one may ask a non-Jew to do so. [Radvaz 1:580 is lenient to buy from a non-Jew safek orlah grapes mixed up and are nullified. Maybe this shows that the Radvaz would be lenient if there’s no option (haarot). Alternatively, there’s no issue of bitul isur lechatchila for something that is only a safek (siman 92).] Brachot 36b implies that it is permitted to buy food from a non-Jew that was cooked in a pot that wasn’t used within 24 hours. That is evident from Rashi s.v. sharya. That is the accepted opinion of many rishonim and poskim but the Meiri in Magen Avot understands the Rambam otherwise. See Yabia Omer 7:7:2.
- Isur Vheter 47:9 writes that it is initially forbidden to buy from a non-Jew an animal that nursed from a non-kosher animal but after the fact it is permitted. Torat Chatat 65:10 cites this. Shach YD 60:5 writes that the reason it is permitted after the fact is zeh vzeh gorem. The Erech Hashulchan 99:8 infers from here that it is forbidden to buy a food that the non-Jew did a nullification in its processing in line with the Radvaz 3:547.
- Rambam Maachalot Asurot 3:13 and 3:15 writes that the cheese of non-Jews is forbidden since they might have used rennet from a nevelah animal which isn’t nullified. Erech Hashulchan infers that had it been nullified it would have been permitted to buy unlike the Radvaz.
- Hagahot Shaarei Dura 1:1:7 asks how it is permitted to buy spices from non-Jews initially since it involves nullification. He suggests that perhaps it is permitted since it was done by a non-Jew.
- The Gemara Avoda Zara 33a states that a container a non-Jew used for wine can be used for a Jew to drink water. The Rashba (Torat HaBayit 36b) explains that since only a tiny bit of the wine taste was absorbed into the containers and it will be nullified when later used to drink water it is permitted. The Rivash (no. 349) and Raavad (cited by Ran Avoda Zara 12b) agree.
- The Raah (Bedek HaBayit 36b) vehemently argues with the Rashba because it should be considered a violation of intentionally nullifying the forbidden absorption in the pots. Rather he explains that the absorption of wine in the containers that the Gemara was discussing is minimal since it is all cold. Also, the wine taste is ruined when it mixes into the water and that isn't considered intentional nullification. The Maadanei Asher (Isur V'heter Siman 81) explains that the Rashba would respond that it isn't forbidden because of intentional nullification unless it is possible that there wouldn't be nullification but if there certainly is nullification, it is permitted.
- The Tur (YD 122) also disagrees with the Rashba but for another reason. He says if the rabbis enacted a decree against using a pot with forbidden taste if 24 hours passed and now the absorption is permitted, how much more so would they enact a decree against using a pot with non-kosher absorption within 24 hours just because it'll be nullified lest one use it for less than the amount that would cause nullification. The Bet Yosef YD 122:5 answers that there's no decree on something uncommon and it is uncommon to use a pot of such a size for a quantity of food less than sixty times the forbidden absorption.
- The Taz 99:15 discusses this Rashba at length and offers two alternate explanations of the Gemara Avoda Zara 33b. Based on Rashi, the water is permitted since it dilutes the wine absorption and ruins it. Additionally, the Ran (Avoda Zara 12b) explains that it is permitted to fill up the wine containers used by the non-Jews for wine in order to Kosher them and even though in the process the water will nullify the wine absorption it is permitted since that isn't one's intent. The Taz concludes in disagreement with the Rashba.
- The Shulchan Aruch YD 99:7 rules like the Rashba and the Kaf Hachaim 99:73 and Aruch Hashulchan 99:49 write that one can rely on the Rashba only if 24 hours have passed.
- Ran Avoda Zara 12b s.v. iybaya posulates that there is no prohibition to nullify something forbidden if one's intention isn't to benefit from the prohibited food. Tosfot Chachmei Angliya Pesachim 30a s.v. ulshmuel, Tosfot Rabbenu Peretz Pesachim 30a s.v. amar rav, Rabbenu Peretz cited in Tur 453:3, Rivash 349, Maharam Mrotenburg (Prague edition n. 190), Rashba (teshuva 463), and Orchot Chaim (Machalot Asurot n. 43, cited by Shulchan Aruch Y.D. 84:13) all have this same approach. Shaar Hamelech (Machalot Asurot 15:25) wonders why the Ran in Pesachim 30a don't address Tosfot's question there the way Rabbenu Peretz answered the question considering that in Avoda Zara he accepts that approach. See Shoel Umeishiv 2:65 who tries to resolve this issue.
- Shulchan Aruch YD 103:1. The two major approaches as to why it is permitted is that of the Ran and that of the Rashba. Ran Avoda Zara 67a explains that one may not benefit from something non-kosher and so if it is intact it is forbidden unless it isn't fit for human consumption. However, if its taste is absorbed in a mixture it is permitted as long as it imparts a negative taste since one isn't benefiting from the non-kosher addition. The Rashba Torat Habayit Haaruch 19a argues that the item itself is permitted only if it is inedible and loses its status of a food. But if it is mixed into a mixture it is permitted since there is a nullification of the substance of the food with a simple majority and the taste of the non-kosher doesn't make the mixture forbidden as long as the taste is negative. The concept that a taste is forbidden even if it is nullified by a majority doesn't apply to negative tastes.
- Rabbi Akiva Eiger (Chidushim Chullin 97b n. 7) applies the idea of Rashba requiring a majority even to the absorptions in pots. The Bet Yehoshua 102:6 argues that it only applies to absorptions in foods or foods that were dissolved but not absorptions in pots. Based on his understanding he answers the question of Rabbi Akiva Eiger 1:27 on Shach 102:8.
- The Maharshal (Yam Shel Shlomo 7:48) learns from the Rambam (Maachalot Asurot 15:31) that a mouse in any liquid besides wine, honey, or oil which need to smell nice to be edible are forbidden. There isn't a leniency of noten taam lifgam for a mouse falling into any liquid. Similarly, in 7;49 he is strict about bugs falling into any liquid since we're not sure whether it imparts a negative taste. He admits that the Ran learns that the taste of a mouse is always negative besides for beer and vinegar and the Rashba (Torat Habayit Hakatzar 16b) holds that tastes of bugs are negative for all foods, he disagrees. Taz cites this Maharshal who disputes the Shulchan Aruch 104:3 codifying the Rashba.
- The Rambam and Shulchan Aruch Y.D. 103:4 hold that meat in oil imparts a negative taste and if its taste gets into the oil it is permitted. Shach 102:14 quotes Tosfot avoda zara 38b and many other rishonim who disagree. Shach concludes that we need to be strict. See Badei Hashulchan Biurim on 102:4 who asks why we can't discern what is considered noten tama lifgam based on our tastes.
- The Rambam and Shulchan Aruch 102:4 write that meat in honey imparts a negative taste. Bet Yosef qualifies the Rambam to plain meat but not spiced meat. Rama 102:4 writes that it only imparts a negative taste into mead but not real honey. Shach 103:14 quotes others who agree with the Rama.
- Shulchan and Rama O.C. 447:10. Ramban (Chidushim 30a), Ran, Rabbenu Dovid, Riaz (Pesachim 2:2:6) and Rashbetz (Maamer Chametz 50-51) are lenient. Rashba is strict.
- Sharei Dura 65:1. Hagahot Shaarei Dura 65:1 quotes this also from the Yereyim 69 and Mordechai 674. This is codified by Shulchan Aruch Y.D. 81:7 and is further explained by the Star-K.
- Or Zaruah (Avoda Zara n. 258-9) quotes the Rashbam who learns from the Gemara Avoda Zara 67a that only if the forbidden food imparts a negative taste is it permitted, however, if it imparts a taste that is neither positive or negative it is forbidden. He clearly indicates that it is not the same as if it has no taste at all. Bet Yosef 103:1 quotes the Or Zaruah. Shach 103:2 quotes the Or Zaruah and then brings a proof to the Or Zaruah from the fact that Gid Hanasha requires 60.
- Contenders of the Shach: Minchat Cohen (Tarovet 1:10) argues on the Shach because the Or Zaruah was only strict if there's a taste and it isn't negative, however, food which has no taste doesn't forbid the mixture. The proof from Gid Hanasheh isn't a proof since that is specially forbidden by the Torah even though it is dry as wood. Also, the Yerushalmi was discussing food which imparts a taste which is neither negative or positive. Pri Chadash 103:1 has the same disputes with the Shach, though he takes issue other details in the Minchat Cohen. Minchat Yakov 85:70 agrees.
- Interpretations of the Shach: Dissolved: Pri Megadim S"D 103:2 seems to understand the Shach as discussing a food which has no taste but when it is dissolved into the mixture it needs 60 a rabbinic gezerah since the substance of the food is mixed in. If a food with no taste dissolved into the mixture it is forbidden up to 60, while if it was cooked and removed it would be permitted. It is comparable to which has no taste when cooked and removed but when dissolved imparts a taste. Yad Avraham 103:1 makes a similar distinction. Igrot Moshe 2:24 disagrees with this understanding of the Shach since the Shach's citation of Gid Hanasha implies that he's discussing food with no taste. Even if it dissolved we hold that it is permitted as long as it doesn't impart a forbidden taste (Shach 98:5). While some understand that Shulchan Aruch Y.D. 100:2's ruling that gid hanesheh requires 60 is an indication that he holds like the Ramban who always requires 60 when the forbidden food dissolves (Minchat Cohen 1:10 and Gra 98:7), nonetheless the halacha assumes that we do not accept the Ramban and other explanations are given for gid hanesheh. For example, the Pri Megadim M"Z 100:5 says that Gid Hanesheh is forbidden because of a minimal taste that it imparts when it dissolves.
- Interpretations of the Shach: Min Bmino: Igrot Moshe YD 2:24 says that the Shach is only discussing a mixture of foods of similar tastes, min bmino. According to the Bavli the reason you need 60 for min bmino is just a gezerah because of eino mino, where you need 60 for taam. What is the halacha of min bmino with something that has no taste? Theoretically you’d say it is permitted without 60 since even even the eino mino it wouldn’t have taste. However, the Shach shows from the Yerushalmi Trumot 10:1 that min bmino is a gezerah because people might not identify it correctly. The Yerushalmi uses min bmino as a proof that when there’s taam that’s not lshevach or lifgam that it is forbidden. This implies that min bmino is a gezerah in all cases even if it has no taste. However, Shach would permit if it is eino mino. His proof from gid hanasha is that gid is forbidden up to 60 even though it has no taste, so too everything in mino needs 60 even though it has no taste. Gid even in eino mino is forbidden up to 60 because of a unique gezera that you’ll confuse gid with basar which has taste.
- The Minchat Cohen Tarovet 1:9 writes that the Rambam Machalot Asurot 14:11 implies that eating forbidden food which is inedible is biblically permitted but forbidden rabbinically. He says further that it is even rabbinically permitted if it is mixed into a mixture even if there is a majority of forbidden ingredients as is evident from Shulchan Aruch Y.D. 103:1. Pri Megadim M"Z 103:1 cites this.
- Those who hold of achshevey: Rosh Pesachim 2:1 writes that if someone ate burnt chametz that wasn't edible even to a dog violates a prohibition since he made it significant by eating it. This is further explained by the Trumat Hadeshen responsa 129 and codified by Shulchan Aruch O.C. 442:9.
- Those who don't hold of achshevey at all: Baal Hameor (on Rif Pesachim 5b s.v. ha) explains that chametz which is burnt and inedible is permitted to be eaten. The Maharam Chalavah (Pesachim 21b s.v. vamar), Michtam (Pesachim 21b s.v. lo), Ritva (Pesachim 21b s.v. vamar), Ran (Pesachim 21b s.v. charcho), Talmid HaRashba (Pesachim 21b s.v. charcho), Ri Mnarvona (Pesachim 21b s.v. shcharcho), and Rabbenu Dovid (Pesachim 21b s.v. vamar) agree. The Ritva quotes our teachers and he could be referring to the Raah (footnotes to kovetz klilat yofey). Based on the language of the Rabbenu Dovid it is possible that the Ramban agrees as well. This seems also to be the opinion of the Raavad (on Rif 5b s.v. ha).
- Those who hold it is only rabbinic: Taz 442:8, Mishna Brurah 442:43. Taz explains that it can't be a biblical prohibition since it is shelo kderech achila (Hebrew:שלא כדרך אכילה, lit. not the way of eating), an abnormal way to eat. Shach YD 155:14 cites the Mordechai and Aguda that someone sick is permitted to consume something forbidden in an abnormal way of eating. Shagat Aryeh 75 disagrees based on the Ran that it is forbidden even for someone sick to consume something forbidden in an abnormal way unless it is pikuach nefesh.
- Minchat Cohen Tarovet 1:9 writes that there's no prohibition to eat something that was inedible to humans if it was mixed into a mixture even if the majority is forbidden. Pri Megadim M"Z 103:1, Chok Yakov 442:19, and Mekor Chaim 442:14 agree. See Achiezer 3:33:5 and Yabia Omer YD 8:11 who apply this to gelatin.
- Igrot Moshe OC 2:92, Meor Yisrael Pesachim 21b citing Yad Avraham YD 155, Chevlim Bneeymim 5:4, Chazon Ish 116:8, and Zera Emet 2:48. Shagat Aryeh 75, however, disagrees and holds that achshevey is relevant even to someone who is sick eating it as a medicine.
- Trumat Hadeshen 129, Shulchan Aruch O.C. 442:10, Rama Y.D. 134:13, Magen Avraham 442:15, Mekor Chaim 442:14, Mishna Brurah 442:45
- Shulchan Aruch YD 98:4.
- Rabbenu Peretz (cited by Tur YD 98:4) held that if a metal utensil is partially inside the hot food the entire utensil becomes hot and imparts taste to the food, however, the Tur disagrees. Rama YD 98:4 rules like the Tur. Kaf HaChaim 98:56 writes that one should be strict for Rabbenu Peretz unless there is a large loss.
- Kaf HaChaim 98:48 explains that when discussing food cooked in a forbidden pot we always consider as though the entire pot imparted forbidden taste even if the food only cooked in half of the pot since there is hot moisture which spreads the forbidden taste throughout the pot.
- Shulchan Aruch YD 98:5 and Rama, see next note.
- The Rashba (Torat HaBayit 1b) writes that if a new spoon was used for a prohibited food or a meat spoon was last used for meat more than 24 hours earlier and is then used for milk that day, then it is considered to only have absorbed the taste of the amount of milk it was used for. However, if it was used for meat within 24 hours, then is used for milk and again for meat, then we consider the spoon to having absorbed the forbidden taste up to the full volume of the spoon. He cites the Ramban as holding that a utensil never becomes completely forbidden and only ever receives the amount of forbidden taste it absorbed even if that was within 24 hours. The Bet Yosef 98:5 understands that the Tur follows the Rashba, while the Ran follows the Ramban. Shulchan Aruch YD 98:5 and Rama rule like Rashba. Kaf HaChaim 98:65 agrees. Shach 98:21 rules that in cases of great loss one can rely on the opinion of the Ramban.
- The Taz 98:8 understands the Mordechai cited by the Rama to say that if an earthenware spoon is used it becomes forbidden up to the full volume of the spoon even if was only used for a certain amount. He concludes that one should be strict for the Mordechai.
- Rama 103:2. The Badei Hashulchan 103:28 cites the Gra who explains the reason is that the rabbis forbade using this pot for something for which it will taste good and forbid it.
- Rama 103:2, Badei Hashulchan 103:38
- Rama 103:2, Shulchan Aruch 103:5, Badei Hashulchan 103:62
- Rashba Torat Habayit Haaruch 4:4 38b writes that it is forbidden to ask a non-Jew to cook in his teref pot that wasn’t used within 24 hours since it is considered bitul isur lechatchila. Rashba writes that it is forbidden even after the fact. Shulchan Aruch YD 103:5 and 122:6 quotes the Rashba but not the part that it makes it forbidden after the fact. Even though the Levushei Sarad and Chamudei Doniel say it is forbidden even after the fact like the Rashba, Igrot Moshe YD 2:41 argues that after the fact were lenient.
- Rashba Torat Habayit Haaruch 38a, Meiri in Magen Avot 13 p. 58, Bet Yosef 122:6, Raah 38a, Meiri A"Z 76a, Radvaz 3:617, Sedah Lderech 2:3:7, Mordechai a"z ch. 2, Tosfot Rid a"z 75b, Erech Hashulchan Sefer Hazikaron 50:8, Yabia Omer YD 8:14, Knesset Hagedola 122:26, Pri Megadim S"D 99:7, Bet Shlomo YD 175, Adovat Avoda Avoda Zara 75b, Mor Ukesiah, Zivchei Tzedek 122:15, and Maharil Diskin Kuntres Acharon 129 hold that if the food was cooked in an eino ben yomo pot intentionally the food is forbidden. However, the Tiferet Lmoshe 94:22, Arugot Habosem YD 99:3, and Zayit Raanan Dvar Sheyesh Lo Matirin 3:2 are lenient.
- Pri Megadim Siftei Daat 103:17 writes that even for earthenware vessels they can't be used after 24 hours even though there's no way to kosher them. He is disagreeing with the Nachalat Yakov 23-25, 42. Badei Hashulchan 103:54 agrees with the Pri Megadim.
- Shulchan Aruch Y.D. 93:1
- Chatom Sofer YD 110 writes that if an eino ben yomo meat pot is used for dairy on a fire it would still only be hetera baala since both the meat and milk entered the pot separately bhetera since the meat was eino ben yomo when the milk went in. He adds as a chumra to do hagalah three times. Pitchei Teshuva 121:7 cites the Chatom Sofer. Siach Yakov (Machalei Akum Hechsher Kelim p. 218, Rav Yakov Kassin) agrees. Shulchan Aruch Y.D. 121:4 writes that whenever it is hetera baala even a roasting pot only requires hagalah.
- Shulchan Aruch YD 103:5
- Tosfot Avoda Zara 38b and Ramban Avoda Zara 35 hold that stam kelim einam bnei yoman, we assume that most pots weren't used within 24 hours. Tosfot and Ramban explain that it is based on a safek safeka. There is a safek if it was used within 24 hours and even if it was it could be that the absorption in the pot won't give any taste to the food or that the taste it'll give will be a negative contribution to the taste of the food. Rambam Machalot Asurot 17:22 seems to disagree with this concept and hold that stam kelim are bnei yoman. Kesef Mishna makes this point. Rabbi Akiva Eiger YD 122 notes that this also seems to be the opinion of Rashi Yoma 81b s.v. sharya. Mahari Ibn Chaviv in Tosefet Yom Hakippurim Yoma 81b also makes this point. (Yabia Omer YD 7:7 cites these opinions.) According to this note, it seems that the same can be proven from the Bahag Brachot 36b and Meiri Brachot 36b. However, with respect to that same Gemara source the Smag Mitzvah 27 writes that stam kelim are assumed to be not bnei yoman. Talmidei Rabbenu Yonah Brachot 25b s.v. umirkachat agrees. The Shulchan Aruch YD 122:6 agrees with the Tosfot, Ramban, Smag and Rabbenu Yonah that stam kelim einan bnei yonam.
- Yabia Omer 5:3:2 citing the Dvar Shmuel 320, Radvaz 4:296, Pri Chadash 110, Masa Melech 7:10 that it isn't necessary to ask to find out more information about a safek safeka unlike the Shach 110 Klal 35. Nonetheless, maybe everyone would agree here since it is embarrassing and maybe the owner wouldn't even know the answer.
- Ketubot 9a
- The Binat Adam (Shaar Hakavuah n. 16) writes that the majority for a piece of meat found in the street is determined by the majority of the total amount of meat sold in all of the stores. He explains that the more meat that the likeliness of the meat coming from the kosher stores depends on the amount of kosher meat that transverses this location. His proof is Shekalim 7:1 which according to the Bartenuro depends on the amount of coins that are for korbanot and those designated as shekalim as opposed to the number of buckets designated for each. The Chavot Daat (YD Biurim 110:3) disagrees and holds that the determination of the majority depends on the amount of stores and not the amount of meat. Pitchei Teshuva YD 110:2 cites a large dispute about this question with most holding like the chavot daat. Shaarei Yosher 4:9 explains that the explanation of the Chavot Daat is that the status of the piece of meat became a doubt the minute it left the store it departed from. Therefore, the majority is coming to determine where the piece of meat left from and not the objective status of the piece of meat. He answers Shekalim by applying the principle that a majority made up of disparate part isn't considered a majority at all. See Rama CM 25 and Nodeh Beyehuda CM 2:3. Milchamot Yehuda (Chidushim ch. 7) explains that this dispute is comparable to the dispute about how to determine a majority for dry solid cold pieces. The dispute is regarding whether a majority depends on the quantity of the pieces of meat or to the total volume of the pieces. Similarly, those who think that a majority is amount determining simply majority of the stores regardless of the quantity would likewise consider a majority for the stores without regard to the amount of meat sold in each store. That dispute is quoted in Pitchei Teshuva 109:1 and Chazon Ish. He also compares this dispute to the question of whether halacha is determining by the simple majority of rabbis and whether that depends on the greatness of the rabbis or not. If the quality and greatness of the rabbis aren't of concern that would correspond with the approach that a majority of pieces irrelevant of size and quantity of stores irrelevant of amount of meat sold there form a majority (see Yevamot 14a, Yad Malachi 230-1, Chinuch n. 78). Meor Yisrael Pesachim 7a and footnotes to Tosfot Harosh and Maharam Chalavah discuss if Tosfot Pesachim 7a is a proof against the Binat Adam.