Bishul

From Halachipedia

Forbidden types of Bishul

  1. One who cooks or bakes food or dyes on Shabbat has violated the Melacha of Bishul, one of the 39 melachot. [1]
  2. Roasting and frying are also included in Bishul. [2]
  3. One transgresses Bishul Deoritta once one cooks raw solids up to a third of being cooked and for liquids when one heats it up to 113 degrees Fahrenheit. However, one can also violate the Bishul by continuing to cook the food until it’s fully cooked. [3]
  4. It’s forbidden to cook with any heating element that’s 113 degrees Fahrenheit including kerosene, gas or electric stove, hotplate, steamer, gas or electric oven. [4]
  5. It is forbidden to put any food, liquid or solid, on the fire on Shabbat, whether the food is cold or hot, cooked or raw. [5]
  6. Similarly, it is forbidden to put any food in a pot that's on the fire. [6]

Heating near a fire

  1. It’s permissible to place completely cooked cold solid food or slightly warm liquid (according to Sephardim, boiling liquid) near a fire to remove the chill or warm it up. [7]
  2. Cold liquids that are fully cooked may not be placed in an area where if the food was left there it would reach Yad Soldet Bo unless there’s a great need, such as heating milk for a baby, and one’s intent is only to warm it or remove the chill and one actually removes it before it reaches Yad Soldet Bo. [8]
  3. It’s forbidden to place a piece of bread close enough to the fire that it will toast. [9]
  4. It’s permissible to place food that’s not fully cooked far enough away from the fire that if it was left there it wouldn’t reach Yad Soldet Bo. [10]
  5. It’s forbidden to dry wet clothes by placing them near a heater or radiator. [11]

Cooking in an oven

  1. It’s forbidden to return food to the oven even if it’s cooked and warm. [12]
  2. If there’s a possibility that the food isn’t fully cooked, if the oven door is opened or opened by itself, it’s forbidden to close the oven door, unless the food is removed. However, fully cooked food that was in the oven from before Shabbat may remain there when/if the oven door is opened. [13]
  3. It’s forbidden to use an oven which is thermostatically controlled since opening or closing the door will likely cause the flame to be increased. [14]

Cooking in a Kli Rishon on the fire

  1. It’s forbidden to put any food, liquid or solid, cooked or non-cooked, hot or cold, in a pot on the fire even if one intends to remove it right away. [15]

Cooking on a covered fire

  1. It’s permissible to cover a fire with a metal tray upside down (which both diminishes it’s heat and makes it’s clear that one is not cooking the same one would during the week) and then place a pot of fully cooked food that is still slightly warm (having been on a fire earlier from before Shabbat). [16]

Cooking in a Kli Rishon off the fire

  1. A Kli Rishon is a pot that was in contact with the fire and is still a Kli Rishon if removed from the fire as long as it is 113 degrees. [17]
  2. A ladle can be considered a Kli Rishon if it was inserted in a hot Kli Rishon all the more so if it was left in there. [18]
  3. Food or liquid that’s not fully cooked may not be placed in a Kli Rishon (a pot removed from fire that’s hotter than 113 degrees Fahrenheit) even if the food is hot and the Kli Rishon is off the fire. [19]

Fully cooked liquids

  1. According to Ashkenazim it’s permitted to place a fully cooked liquid in a Kli Rishon that’s off the fire as long as the liquid is still warm (it hasn’t completely cooled since being heated). [20]
  2. According to Sephardim, it’s permissible to pour fully cooked hot liquid into a Kli Rishon only if the liquid is still 113 degrees. [21]
  3. Fully cooked liquid that has cooled (since it was heated originally while cooking) even if it became warm after it was cooked, it may not be placed in a Kli Rishon and the contents of a Kli Rishon may not be poured into in. [22]

Fully cooked solids

  1. A fully cooked solid even if it’s cold may be placed in a Kli Rishon if the pot is not on the fire. [23]
    1. A fully baked (dry heat), roasted, or fried food may not be cooked(liquid heat). According to Ashkenazim one may not cook the baked, roasted or fried food in a Kli Rishon or Kli Sheni. [24]
    2. According to Ashkenazim, it’s forbidden to put any baked item such as croutons, soup nuts, challah, or matzah in hot soup that was poured directly from the pot. However it is permitted to place a baked food in soup that’s was poured into a bowl through a ladle that wasn’t left in the soup for any length of time. [25]
  2. According to Ashkenazim, it is forbidden to put a cooked or boiled food such as chicken on top of a blech. [26]

Non-fully cooked food or liquid

  1. It’s forbidden to put any non-fully cooked food, liquid or solid, in a Kli Rishon even if it’s off the fire. [27]
  2. It’s permissible to place a baby bottle of milk in a Kli Rishon which is off the fire and there’s a lot of milk in the bottle that it’s impossible that the milk will reach 113 degrees (if left in the Kli Rishon). [28]
  3. It’s permissible to pour a large amount of cold water into hot water in a Kli Rishon (which is off the fire) as long as the mixture thereby becomes less than 113 degrees and that the pouring is done in one swift action. [29]

Transferring food from one pot to another

  1. It’s permissible to transfer food from one pot on the fire to another pot that’s on a covered fire if the food in both pots are fully cooked. [30]
  2. If one’s fully cooked food is drying out one may pour boiling water from an urn into a pot that’s on the fire. If that’s not possible it’s permitted to take water with a ladle or spoon and pour it into the pot. [31]
  3. It’s permissible to separate fully cooked in one pot on the fire into two pots as long as the empty one was clean and dry and one complies with the rules of chazara. [32]


http://www.dailyhalacha.com/displayRead.asp?readID=577 concerning placing a hot pot on top of a wet counter.

Pouring from a Kli Rishon

  1. It’s forbidden to pour from a Kli Rishon onto cold liquid or non-fully cooked solids. [33]
  2. It’s permissible to pour from a Kli Rishon onto a baby bottle filled with milk (even if it’s cold and uncooked) since the pouring only cooks the outer layer and in this case it’s the bottle (which doesn’t cook at this temperature), however, one should be careful that the bottle isn’t completely covered by the hot water. [34]
  3. It’s permissible to pour hot water from a Kli Rishon into a large amount of cold water as long as the cold water will thereby heated to 113 degrees. [35]
  4. It’s forbidden to pour hot water from a Kli Rishon onto regular sugar, saccharin, instant coffee, soup powder, instant cocoa, or uncooked tea leaves. [36]
  5. It’s permissible to pour from a Kli Rishon (even if it’s on the fire) onto fully cooked solids or fully cooked liquids which are still slightly warm. [37]
    1. Therefore, it’s permissible to pour from an urn onto tea essence which is still warm.

[38]

Removing food from a pot on the fire

  1. For foods which have not yet been fully cooked, one may not remove a portion since it reduces the amount of food and hastens the cooking. [39]
  2. Similarly, it’s forbidden to take water out of an urn in which the water has not reached its boiling point yet. [40]

Removing a utensil and stirring a hot food

Not fully cooked food

  1. It’s forbidden (as Deoritta Bishul) to stir hot food that isn’t fully cooked when it’s on the fire or removed from the fire as long as it’s 113 degrees in a Kli Rishon. [41]
  2. One can’t even take out a serving utensil from a Kli Rishon (even off the fire), unless the food is cold (not at the level of 113 degrees). [42]

Fully cooked food

  1. Actually mixing fully cooked food which is on the fire is forbidden. [43]
  2. Ashkenazim are strict not even to take a serving spoon out of a pot of a fully cooked food (that’s 113 degrees) only while it’s on the fire. [44] However, Sephardim hold it’s permitted even if in the act one turns the food that was on top of the pot to be moved to the bottom closer to the fire. [45]

Food not on the fire

  1. If the fully cooked food is off the fire, or it’s on a Blech, one can completely mix the food. [46]
  2. It is permitted to put a spoon or ladle inside a pot taken off the fire as long as one is careful that the spoon or ladle is free from any remnants of water or uncooked food. [47]

Cooking on an electric stove

  1. It’s forbidden to place anything on an electric stove unless it is covered. [48]
  2. Before Shabbat, it’s permissible to leave cooked food on a covered electric stove which is set on a timer to begin operating on Shabbat. [49] In such a case, one may not place food on the covered stove on Shabbat even before it began operating. [50]

Cooking in a Kli Sheni

  1. It’s forbidden to put any non-cooked food into a Kli Sheni which has the temperature of 113 degrees or greater. [51]
  2. Certain foods (such as potatoes, meat, kugel, or whole beans) store heat and should be treated as a Kli Rishon as long as it’s 113 degrees even if transferred to a Kli Sheni or Shelishi. [52] For example, one shouldn’t put butter or seasoning on a hot (113 degree) potato or piece of meat. [53] An exception to the rule, is that salt and some say even ketchup may be placed on the hot foods. [54]

Which foods may be placed in a Kli Sheni?

  1. Two exceptions to the rule of placing liquids in a Kli Sheni are oil and water which may be placed in a Kli Sheni. [55]
  2. It’s permitted to place sugar, saccharin, instant coffee, soup powder, milk powder, instant cocoa, table salt, or cooking salt into a Kli Sheni as they have been cooked in the manufacturing process. [56]
  3. It’s forbidden to place tea leaves or ordinary cocoa in a Kli Sheni. [57]
  4. A fully baked (dry heat), roasted, or fried food may not be cooked (liquid heat). According to Ashkenazim one may not cook the baked, roasted or fried food in a Kli Rishon or Kli Sheni. [58]

Fully cooked liquid

  1. Fully cooked liquid (whether it is warm or cold) may be placed in a Kli Sheni for example, tea essence, and there is what to rely on regarding pasteurized milk. [59]

Pouring from a Kli Sheni

  1. One may pour from a Kli Sheni onto fully cooked liquid (whether it is warm or cold) [60]
  2. One should not pour hot water (which has the temperature of 113 degrees) from a Kli Sheni onto a raw egg, non-boiled tea leaves, or herring. [61]

Cooking in a Kli Shelishi

  1. Some forbid putting tea leaves in a Kli Shelishi, and some permit. According to those who forbid, one should make tea essence before Shabbat and pour it into hot water of a Kli Sheni on Shabbat. [62]
    1. Some say there’s an issue of putting tea leaves in a kli rishon on Shabbat even if they were put in boiling water before Shabbat. However if the leaves were totally cooked there’s no issue of putting them in a kli rishon on Shabbat. [63]
  2. A fully baked (dry heat), roasted, or fried food may be cooked(liquid heat) in a Kli Shelishi. Therefore if soup was ladled from a pot into a bowl it’s permissible to place bread in the bowl. [64]

Cooking in a Microwave

  1. It’s forbidden to cook in a microwave on Shabbat. [65]

Water heaters or boilers

  1. Many water heaters (or boilers) are made so that automatically when hot water is removed cold water is added, if this is the case, it’s forbidden to remove hot water even if the water heater (or boiler) is turned off. [66]

Covering a pot

  1. It’s forbidden to cover a kli rishon while it’s 113 degrees if the food isn’t surely fully cooked whether the pot is on the fire or off the fire. [67] If the pot contains chicken bones, they have to be sufficiently soft to be edible in order for the pot’s food to be considered fully cooked. [68]

One pot on top of another

  1. Food which isn’t fully cooked may not be placed on top of another pot which is on the fire. [69]
  2. It’s permissible to place a pot of cold food on top of another pot (which is on top of the fire) in order to remove it’s chill only if there’s no chance that the pot will reach Yad Soldet Bo if left it was left there. [70]
  3. It’s permissible to place a pot of solid food on top of another pot which is on a fire as long as the food is fully cooked. If the food is liquid, it must be fully cooked, and according to Sephardim, the liquid must be Yad Soldet Bo, however, according to Ashkenazim, the liquid must be warm (and not cold). [71]
  4. It’s forbidden to place a pot on top of another pot where the top pot contains food with containing large quantities of congealed fat. However, if there’s only a little congealed fat such that when melted it mixes with the rest of the food it’s permissible. If fat was dissolved it may be eaten. It’s also permitted to dissolve a sauce that is normally eaten in it’s congealed state such as fish sauce. [72]

Gas leak

  1. If the flame on the stove goes out and the gas is escaping, it’s permissible to turn off the tap. Preferably this should be done with a variation (such as using the back of one’s hand, or one’s elbow). [73]

Yom Tov

  1. It’s permissible to cook on Yom Tov as long as the flame was lit before Yom Tov or the timer was set for it to begin operating on Yom Tov. [74]
  2. One may not raise or lower the temperature of an electric stove. [75]
  3. On Yom Tov, an oven which is thermostatically controlled, is permitted to be opened and closed in order to put in, check, or remove food. [76]


Examples

Tea

  1. some say there’s an issue of putting tea leaves in a kli rishon on Shabbat even if they were put in boiling water before Shabbat. However if the leaves were totally cooked there’s no issue of putting them in a kli rishon on Shabbat. [77]

References

  1. Mishna (Shabbat 73a) says baking bread is one of the 39 melachot. The Gemara 74b includes cooking dyes in the melacha as well. This is brought as halacha in Rambam (Shabbat 9:1) and Tur 318:1.
  2. Rambam (Shabbat 9:5) counts both roasting and frying as Bishul and the Iglei Tal (Ofeh 1:1) explains that Rambam is counting ways to violate the Av in the first five Halachot of the chapter and from there and on he counts Toldot. However Lechem Mishna (Shabbat 8:12) says that since there’s no Nafka Minah between an Av and Toldah the Rambam wasn’t specific about differentiating them. Either way, these methods of cooking are forbidden deoritta, so writes Shemirat Shabbat KeHilchata 1:1.
  3. Shemirat Shabbat KeHilchata 1:5
  4. Shemirat Shabbat KeHilchata 1:1,4
  5. Shemirat Shabbat KeHilchata 1:12
  6. Shemirat Shabbat KeHilchata 1:12
  7. S”A 318:15 writes that totally cooked cold solids and boiling liquids may be placed near the fire even in an area where it could reach Yad Soldet Bo. Rama 318:15 writes that the minhag is to be lenient regarding reheating liquids as long as it’s slightly warm. So writes Shemirat Shabbat KeHilchata 1:13, Shabbat Kitchen (pg 43).
  8. Shemirat Shabbat KeHilchata 1:13
  9. Shemirat Shabbat KeHilchata 1:62
  10. Shemirat Shabbat KeHilchata 1:13
  11. Shemirat Shabbat KeHilchata 15:9-11
  12. Shemirat Shabbat KeHilchata 1:17
  13. Shemirat Shabbat KeHilchata 1:17
  14. Shemirat Shabbat KeHilchata 1:29
  15. Shemirat Shabbat KeHilchata 1:12
  16. Shemirat Shabbat KeHilchata 1:23
  17. Shemirat Shabbat KeHilchata 1:2
  18. Shemirat Shabbat KeHilchata 1:48
  19. Shemirat Shabbat KeHilchata. 1:6
  20. Mishna Brurah 318:24 bringing the Rama 318:15 even in the case of a Kli Rishon, Shemirat Shabbat KeHilchata. 1:7,15, Shabbat Kitchen (pg 41-3)
  21. S”A 318:4 writes that if the liquid has cooled it may not be poured into a kli rishon. Mishna Brurah 318:24 explains that it must be Yad Soldet Bo according to S”A in order to pour it into a kli rishon.
  22. Shemirat Shabbat KeHilchata. 1:8(1)
  23. S”A 318:4, Shemirat Shabbat KeHilchata 1:10, 15, Shabbat Kitchen (Rabbi Simcha Bunim Cohen; pg 43)
  24. S”A 318:5 brings two opinions and Rama writes that the Minhag is to be strict even in a Kli Sheni. Shemirat Shabbat KeHilchata 1:59 holds like the Rama that it’s forbidden even in a Kli Sheni.
  25. Shemirat Shabbat KeHilchata 1:59 holds like the Rama that it’s forbidden even in a Kli Sheni, however he considers the soup in the bowl a Kli Shishi if the soup was taken through a ladle that wasn’t left in the soup for any length of time. This is also codified in Hilchot Shabbat pg 263 by Rabbi Shimon Eider and Shabbat Kitchen pg 38 by Rabbi Simcha Bunim Cohen.
  26. Mishna Brurah 318:41 and Shemirat Shabbat KeHilchata 1:60 writes that since the chicken or cooked food was cooked originally with wet-heat and now it’s being cooked through dry heat like roasting it’s forbidden to heat up the food.
  27. Shemirat Shabbat KeHilchata 1:14
  28. Shemirat Shabbat KeHilchata 1:50
  29. Shemirat Shabbat KeHilchata 1:52
  30. Shemirat Shabbat KeHilchata 1:16
  31. Shemirat Shabbat KeHilchata 1:16
  32. Shemirat Shabbat KeHilchata 1:16
  33. Shemirat Shabbat KeHilchata 1:46
  34. Shemirat Shabbat KeHilchata 1:50
  35. Shemirat Shabbat KeHilchata 1:51
  36. Shemirat Shabbat KeHilchata 1:46,9
  37. Shemirat Shabbat KeHilchata 1:47
  38. Shemirat Shabbat KeHilchata 1:47
  39. Shabbat Kitchen (Rabbi Simcha Bunim Cohen; pg 8)
  40. Shabbat Kitchen (Rabbi Simcha Bunim Cohen; pg 8), Shemirat Shabbat KeHilchata (1:35 note 96)
  41. In Shabbat 18b, the Gemara says that there’s no issue of Megis (stirring) a hot food if the pot is totally sealed with cement implying that stirring a hot food is forbidden as Bishul, cooking (Rashi 18b D”H Megis). Rambam 3:11, S”A 318:18, and Shemirat Shabbat KeHilchata 1:31 bring this law as halacha.
  42. When Rambam 3:11 and S”A 318:18 quote the law of stirring, they extend it to the case of removing a serving spoon from a hot food which causes a mixing of the food. Bet Yosef explains that when the Rambam forbids by a pot on the fire, it also includes the case of where the pot came off the fire and is still boiling. This is found explicitly in the Ran 6b and Rabbenu Yerucham 3:12 pg 68a. S”A rules this law with the language of a pot removed from the fire. This is brought as halacha in Shemirat Shabbat KeHilchata 1:31.
  43. Ritva Shabbat 18b (quoted in Tal Orot pg 39) writes that even after the food was cooked it’s still forbidden on a rabbinic level to stir the hot food. S”A 318:18 rules one can’t remove a spoon from a food that’s not fully cooked but if it’s fully cooked it’s permitted, which seemingly means that one can remove a spoon from a fully cooked food but not to actually mix it. Similarly, Bet Yosef 321 quotes Sh”t Rambam 68 (and the halacha is also found in Shabbat 21:13) who permits mixing a hot food that was fully cooked and removed from the fire. Bet Yosef adds that even though it’s forbidden even off the fire as long as it’s hot here it’s permitted because it’s totally cooked. Rav Ovadyah (Yalkut Yosef Shabbat vol 3 pg 187; Kol Sinai Tevet 5723) implies from these sources that actually mixing a totally cooked food while on the fire is forbidden as Mechzei KeMevashel (appears like cooking). Or Letzion 2 pg 238 writes that the Kol Bo (quoted by Bet Yosef 253) who forbids stirring a fully cooked pot on the fire is a Deoritta prohibition, while Mishna Brurah 318 argues that clearly stirring a fully cooked food is only forbidden on a rabbinic level (as is explicit in the Ritva). However, Ramach (quoted by Kesef Mishna 9:4), Mamer Mordechai 318:20, and Chazon Ish 37:15 permit actual mixing even though the pot is on the fire because the food is completely cooked.
  44. Ran 6b (according to the version of the Bet Yosef 318:18 quoted by the Hagot HaBach on the Rif) writes that even removing a serving spoon from the pot of hot food is forbidden because in that act one stirs the food. Rambam 3:11 also rules that putting a serving spoon is forbidden because of stirring. However, Magid Mishna 3:11 explains that that Rambam (and Ran who says this explicitly) only forbad a hot food that wasn’t totally cooked but stirring is permitted if it’s totally cooked (Bet Yosef adds that according to those who hold there’s no issue of cooking once it’s cooked to the stage of Machal Ben Dursai, here too, stirring is permitted at Machal Ben Dursai). [Interestingly, Maggid Mishna 9:4 says in name of Ramban (18b D”H VeHalo Megis) and Rashba (18b D”H Tzemer LeYurah) that once the hot food was stirred once it’s considered cooked and there’s no issue of cooking with the second stirring.] S”A 318:18 rules that it’s permitted to remove a spoon from a fully cooked food even when it’s on the fire. However, the Rama is strict not to remove a utensil or stir the pot whether it’s on the fire or even off the fire based on Sh”t Mahari Vill 30. The achronim including Eliyah Raba 318:40, Chaye Adam 20:9, Levush 321:9, Pri Megadim M”Z 321:23, Sh”t Zera Emet 1:40, Tehilat LeDavid 252:1, Mishna Brurah 318:117, and Shemirat Shabbat KeHilchata 1:32 agree that Ashkenazim should be strict like the Rama while the food is still on the fire both not to stir and not to remove a utensil (and they mention that if there’s one who wants to be stringent one should be stringent in regards to stirring something off the fire). Sh”t Igrot Moshe 4:74 is strict like the Rama regarding food that’s on the fire and explains that that one may not stir food on the fire so that one doesn’t assume that the food is totally cooked and it really isn’t and come to a Torah prohibition. Shemirat Shabbat KeHilchata 1:32 adds that if there’s going to be non way to remove food from the pot and return it to the fire (because of absence of a suitable cover of the fire) one may be lenient and remove food (not stir) as long as the food is surely fully cooked.
  45. See above note. The Chida in name of the Radvaz 3:411, Taz 318:23, and Yalkut Yosef (Shabbat vol 3 pg 187) rule like S”A. [Interestingly, Orchot Rabbenu Kehilat Yacov pg 149 writes that in the house of the Chazon Ish and Kehilat Yacov (who were Ashkenazic), they actually took food from a pot on the fire when the food was fully cooked, not like the Rama (however, Orchot Rabbenu explains that since they were so strict regarding Chazara, if they weren’t lenient in this regard, they wouldn’t have hot food on Shabbat). The Chazon Ish 37:15 actually rule this way. ]
  46. Bet Yosef 321 quotes Sh”t Rambam 68 (and the halacha is also found in Rambam Hilchot Shabbat 21:13) who permits mixing a hot food that was fully cooked and removed from the fire. S”A 318:18 rules that it’s permitted to remove a spoon from a fully cooked food even when it’s on the fire, implying when off the fire and it’s fully cooked one can actually stir the food. Yalkut Yosef (Kitzur S”A vol 1 pg 631), and Shemirat Shabbat KeHilchata 1:32 rule that once the food is off the fire, one may stir the food. [Mishna Brurah 318:117 writes that if one want to be strict one shouldn’t stir it but just remove the food from the pot.]
  47. Shemirat Shabbat KeHilchata 1:34
  48. Shemirat Shabbat KeHilchata 1:24
  49. Shemirat Shabbat KeHilchata 1:26
  50. Shemirat Shabbat KeHilchata 1:26
  51. Shemirat Shabbat KeHilchata 1:53
  52. Shemirat Shabbat KeHilchata 1:58
  53. Shemirat Shabbat KeHilchata 1:58
  54. Shemirat Shabbat KeHilchata 1:58
  55. Shemirat Shabbat KeHilchata 1:53
  56. Shemirat Shabbat KeHilchata 1:49, 54
  57. Shemirat Shabbat KeHilchata 1:53
  58. S”A 318:5 brings two opinions and Rama writes that the Minhag is to be strict even in a Kli Sheni. Shemirat Shabbat KeHilchata 1:59 holds like the Rama that it’s forbidden even in a Kli Sheni.
  59. Shemirat Shabbat KeHilchata. 1:8(2), 1:55, Mishna Brurah 318:39(end) regarding tea essence and milk
  60. Shemirat Shabbat KeHilchata. 1:8(2)
  61. Shemirat Shabbat KeHilchata 1:57
  62. Chazon Ish 52:19, Aruch HaShulchan 318:28, Shabbat Kitchen (Rabbi Simcha Bunim Kohen; pg 32) hold that tea leaves are food that are easily cooked and a Kli Shelishi is no different than a Kli Sheni. However, Igrot Moshe 4:74 bishul#15 permits putting tea leaves in a Kli Shelishi since he holds that a Kli Shelishi can’t cook at all. According to those who forbid, Mishna Brurah 319:39 writes that one should make tea essence before Shabbat and then pour it into hot water of a Kli Sheni on Shabbat. See Sh”t Shevet Halevi 1:90 who argues on the advise of the Mishna Brurah to cook the leaves before Shabbat and then again on Shabbat because Sh”t Maharam Shik 132 suggest that there may be bishul acher bishul with the tea leaves.
  63. Sh”t Shevet HaLevi 1:90
  64. Shemirat Shabbat KeHilchata 1:59
  65. 39 Melachot (Rav Ribiat; pg 589), Sh”t Igrot Moshe 3:52, Shabbat Kitchen (Rabbi Simcha Bunim Cohen; pg 2)
  66. Shemirat Shabbat KeHilchata 1:39
  67. Shemirat Shabbat KeHilchata 1:35(1)
  68. Shemirat Shabbat KeHilchata 1:35(2)
  69. S”A 318:7-8 brings a dispute whether one may place a pot with cold solids or hot liquids which are Yad Soldet Bo on top of a pot that’s on the fire and rules leniently. Even though the Taz 318:11 writes that it’s permissible even if it’s not fully cooked (but seems to require that the pot will not be able to cook), Mishna Brurah 318:55 rules that the food must be fully cooked based on the Achronim (Bach, Gra, Tosefet Shabbat, Olat Shabbat, Maamer Mordechai, Pri Megadim) who disagree with the Taz 318:9 on a similar issue. Shemirat Shabbat KeHilchata 1:36 rules like the Mishna Brurah.
  70. Buir Halacha 318:6 D”H Ad SheTehe, Shemirat Shabbat KeHilchata 1:36
  71. S”A 318:7 brings a dispute whether one may place a pot with hot liquids which are Yad Soldet Bo on top of a pot that’s on the fire. S”A 318:8 quotes the same dispute regarding solids except that the food doesn’t need to be hot and even if the food can reach the temperature of Yad Soldet Bo. S”A rules that for both the previous issues the halacha is like the lenient opinion. So rule the achronim including Gra 318:7, Eliyah Rabba 318:21, Mishna Brurah 318:60, Shemirat Shabbat KeHilchata 1:36, and Yalkut Yosef (Shabbat vol 3 pg 207). Even though 318:7 writes that liquids must be as hot as Yad Soldet Bo, Rama 318:15 argues that even if it’s just slightly warm it’s permissible. So rules Shemirat Shabbat KeHilchata 1:36. [However, Chazon Ish 37 writes that an empty pot isn’t considered a separation between the pot of food and the fire. So holds Sh”t Az Nidbaru 3:14 and Shabbat Kitchen (Rabbi Simcha Bunim Kohen; pg 42) that the bottom pot must be filled with food. However, Sh”t Shevet HaLevi 1:91 defends the minhag.]
  72. Shemirat Shabbat KeHilchata 1:37
  73. Shemirat Shabbat KeHilchata 1:28
  74. Shemirat Shabbat KeHilchata 1:27
  75. Shemirat Shabbat KeHilchata 1:27
  76. Shemirat Shabbat KeHilchata 1:30
  77. Sh”T Shevet HaLevi 1:90