Kashering the kitchen for Pesach
Which materials can be kashered?
- It is possible kasher wooden, metal, or stone utensils. It is impossible to kasher earthenware utensils. 
- If a vessel was used even once for Chametz it needs to be cleansed to be used for Pesach. A bread knife which was once for cutting a Chametz food that was hot such as warm cake, warm breaded-chicken, or used to stir chulent. A teapot needs be cleansed because it probably touched Chametz when it was warm. 
- There is a question if it is possible to kasher plastic utensils. 
- The Ashkenazic minhag is not to kasher glass. According to Sephardim, one never needs to kasher glass, as it does not absorb. Rather, one must wash it thoroughly. The same is true for Pyrex and Duralex.
- If a vessel is used a majority of the time for cooking in liquid it is cleansed through boiling water. 
- Hagalah includes cleaning the pot well from all Chametz, then immersing it in (boiling) hot water in a pot that’s on the fire (or an electric heating source) or a pot that was just removed from the fire. 
- The minhag is to wash the utensils in cold water after performing Hagalah. 
- If a utensil is used over the fire a majority of its uses such as the oven racks it is cleansed through making it red hot. 
- Grills and skewers need Libun since it probably touched meat that was mixed with Chametz and should be heated until it sparks. 
- An electric or gas oven should be cleaned from all specks of Chametz and left 24 hours unused. If it has a self-cleaning mode, it should be put on self-clean and that is sufficient. However, if it doesn't have self-clean, many hold that the oven can be heated to the highest temperature it reaches for one hour or two and that is sufficient.  Some hold that ovens which don't have a self-clean setting can't be koshered for Pesach. In practice, one should consult one's rabbi.
- Racks of electric ovens should be cleansed with Libun and if one does it with Hagalah one has to what to rely on. 
- If one isn’t going to put any hot food on the counters on Pesach, it is sufficient to clean the counters very well. If one is going to put hot food on the counters on Pesach, one should clean and cover the counters. Regarding kashering the counters, see the footnote. 
- Microwave which heat up food like an oven are cleansed like an oven by having it cleaned from all Chametz, left unused for 24 hours, and then heated to it’s highest temperature for an hour. 
- Microwaves which are used to heat up food by radiation then if the microwave walls are made out of metal, many hold that one can kasher the microwave by cleaning it thoroughly and boiling a cup of water in the microwave until it steams. If the walls are made out of plastic, many say that one can follow the above procedure and then cover the food put in the microwave on Pesach. 
- If the walls of the dishwasher are made out of plastic or porcelain, many hold that one cannot kasher the dishwasher. 
- According to Sephardim, a dishwasher which is used with soap can be used on Pesach but it’s preferable to run a cycle without dishes with soap. 
- Frying pans which one uses with a little oil should be cleansed with Libun but one has what to rely on to cleanse it with Hagalah. 
- Pans used to bake cakes with a little oil should not be used on Pesach because doing Libun on it will break it and one has what to rely on to do Hagalah. 
- One should purchase new baby bottles for pesach. 
- According to Sepharadim, dentures need only be cleaned well.
- Kashering the kitchen for pesach by Rabbi Hershel Schachter
- Kashering keilim for pesach by Rabbi Zvi Sobolofsky
- Article on Kashering utensils for pesach by Rabbi Josh Flug
- Kitzur Shulchan Aruch 116:1-2
- Yalkut Yosef (Isser VeHeter vol 3 pg 470)
- Rav Shimon Eider in Halachos of Pesach (p. 137) rules that one may not kasher plastic utensils for Pesach based on Igrot Moshe 2:92 who doesn’t allow kashering synthetic rubber since it is a new material that wasn’t discussed by the Rishonim. See however, Chazon Ovadia (p. 151), Minchat Yitzchak 3:67, Chelkat Yaakov YD 45, Tzitz Eliezer 4:6 who allow kashering plastic.
- Kitzur Shulchan Aruch 116:13
- Yechave Daat 1:6
- Chazon Ovadyah (pg 124)
- Chazon Ovadyah (pg 136)
- Kitzur S”A 116:17
- Chazon Ovadyah (pg 124)
- Chazon Ovadyah (pg 126)
- Rabbi Jachter (Gray Matter vol. 2, p. 221) quoting Rabbi Elazar Teitz, CRC Pesach Guide 2016 (p. 19), OU Pesach Guide 2016 p. 24.
- Rav Ovadia Yosef (Chazon Ovadyah pg 73, Sh”t Yechave Daat 2:63), Rav Aharon Kotler (quoted by Rabbi Eider in Halachos of Pesach 1:180), and Rav Soloveitchik (quoted by Gray Matter vol. 2, p. 219) hold that conventional ovens which don't have a self-cleaning setting can be koshered by raising them to the highest temperature that they can reach for an hour or two.
- Rav Ovadia Yosef explains that according to many rishonim chametz is considered something which is permitted that was absorbed in a utensil that only becomes forbidden over time and as such even items which normally would require libun can suffice with hagalah. Even though Shulchan Aruch O.C. 451:4 holds like the rishonim who hold that chametz is considered like a forbdiden taste all year since on Pesach it will be forbidden and as such libun is necessary on utensils used over the fire, nonetheless, for utensils which can't be koshered any other way and it is difficult not to use the oven all of Pesach, one can rely on the lenient opinion. See Rav Ovadia's responsa for his lengthy explanation.
- Rabbi Soloveitchik offered another reason to be lenient. Since chametz only got absorbed through a certain temperature, those absorptions can be removed in the same way that they went in, which is certainly less than the maximum temperature that the oven can reach. This seems to be at odds with the Pri Megadim E"A 451:30 who holds that libun needs to be a certain temperature to burn out the forbidden tastes, but it is supported by the Arugot Bosem 119.
- CRC Pesach Guide 2016 (p. 19) writes that for non-self cleaning ovens one should heat it to the highest temperature it could reach for one hour after waiting 24 hours. Additionally, the racks and grates should be covered with aluminum foil perforated for air circulation and no food should touch the side bottom or top of the oven on Pesach.
- Rav Jachter (Gray Matter vol. 2, p. 218) and OU Pesach Guide 2016 p. 26 quoting Rav Mohe Feinstein
- Chazon Ovadyah (pg 132-4)
- The Tur and S”A 451:20 write that the minhag is to pour hot water on the tables and cabinets used for food during the year because sometimes hot liquid chametz spills onto them. The Magen Avraham 451:38 quotes the Maharil who records the minhag to cover the tables and cabinets after this kashering procedure because perhaps some actual chametz was stuck onto the table or cabinet.
- Kaf HaChaim 451:233 notes that wooden tables which one always eats on with a tablecloth don’t need to be kashered and one should simply remove the actual chametz and wipe down the surface. Rav Mordechai Willig (“Shiur 64 – Pesachim” min 80-82) says that strictly speaking this is also true for countertops on which people don’t put chametz directly. Rav Hershel Schachter (OU Pre-Pesach Webcast 5769, min 11-13) adds that one could either kasher the counters or cover them, but if one isn’t going to put any hot food on the counters on Pesach one could simply clean the counters well.
- Thus, Rav Moshe Feinstein (quoted by Halachos of Pesach p. 140) maintains that one should not kasher Formica countertops, which are made out of hardened plastic, rather these should be washed and covered.
- Yalkut Yosef (Kitzur S”A 451:10)
- The Mishna (Avoda Zara 75b) writes that utensils, which absorbed the taste of forbidden food through fire, can be purified through Libun. Tosfot (Chullin 8a s.v. SheLivna) explains that since when chametz is absorbed into the utensils before Pesach the chametz taste was permitted, utensils that usually required Libun, can be kashered with Hagalah. The Ran (Pesachim 8b s.v. Devarim) explains that the Rif considers chametz taste to be a forbidden taste since it has a status of chametz even before Pesach. Although S”A and Rama 451:4 rule stringently, the Mishna Brurah 451:32 notes that in some cases we rely on the lenient opinions.
- Yalkut Yosef (Moadim p. 600-8, Pesach p. 38) writes that if a microwave is used mostly to reheat and the walls of the microwave don’t reach a temperature of Yad Soledet Bo, one could kasher it by heating up a cup of water with some soap in the microwave for a few minutes.
- He explains that since most of the time the microwave doesn’t reach Yad Soledet Bo it may not require kashering. Even if it does reach Yad Soledet Bo, heating up water in the microwave until it steams up the microwave is considered Hagalah. He reasons that steam suffices since the taste was only absorbed through steam. He adds several other reasons to be lenient with absorptions through steam such as perhaps the walls don’t absorb through steam, perhaps steam applies only to liquid foods, and perhaps steam absorptions are only d’rabanan altogether. He adds that it is still preferable to cover foods on Pesach in the microwave. Lastly, if the microwave is mostly used to cook or is a commercial microwave that is used very frequently and the walls usually reach Yad Soledet Bo, it shouldn’t be used on Pesach.
- Rav Moshe Feinstein (quoted by Halachos of Pesach p. 182) agreed that a microwave can be kashered with steam just as it absorbed through steam. Rav Mordechai Willig (“Shiur 64 – Pesachim” min 66-8) agrees if the walls are metal the microwave can be kashered with steam, but if the walls are plastic it shouldn’t be kashered. Rav Hershel Schachter (“Kashering the Kitchen for Pesach” min 10-13) said that if the walls are plastic one could kasher it with steam as long as one covers one’s food on Pesach because it is improbable that forbidden taste is transferred in the air. Similarly, Rav Shimon Eider (Halachos of Pesach p. 182) writes if the walls are plastic one may cover the interior completely and cook in it when the food is covered.
- Rav Hershel Schachter (“Kashering the Kitchen for Pesach” min 13-15) said that dishwashers which have a plastic or porcelain walls can not be kashered for Pesach, however, the stainless steel ones can kashered but one must be sure to remove all the particles of chametz stuck in the drain. Halachos of Pesach (p. 175) agrees. See, however, Yalkut Yosef (451:11) who writes that dishwashers can be kashered by cleaning it well and running an empty cycle with soap.
- Yalkut Yosef (Kitzur S”A 451:11)
- Yechave Daat 1:7 Chazon Ovadyah (pg 134)
- Yechave Daat 1:7, Yalkut Yosef (Kitzur S”A 451:13)
- Yechave Daat 1:8