Chapter 5:

Koshering the Kitchen

Chapter 5:

Koshering the Kitchen

  1. Principles
  2. When a chametz food item is cooked in a utensil, the utensil generally will absorb the taste of the chametz food item cooked inside of it.1
  3. The basic rule of koshering chametz cooking utensils is to remove the chametz taste in the same manner it was absorbed.2
  4. There are three general levels of koshering via heat:
  5. Libun gamur or “complete burning”– via direct contact with fire so that the chametz taste is completely burned within the walls of the vessel3
  6. Libun kal or “light burning” via indirect contact with fire so that the chametz taste is burned out on a less intense level4
  7. Hagalah or “boiling water method” – an equivalent level to libun kal,5 where the chametz taste is cooked out via boiling water6

Major and Minor Appliances

  1. Regarding the interior of an electric or gas oven: Inspect for and clean/spray any edible chametz with an astringent cleanser and then set the oven to its highest7 temperature8 for approximately 30 minutes.9 Alternatively, you can run a self-cleaning cycle (if this is a viable option.)10
  2. Grates: If there are grates on the burners where a pot or pan is placed, these can be koshered by cleaning them and then placing a pot or pan on top of the grate as it is normally used (so the heat is extended to the entire area it usually reaches), with water inside so the pot or pan does not burn, for about 3-5 minutes (enough time for the burners to get very hot.)11
  3. Stovetops (including glass cooktops): These should be cleaned well with an astringent cleanser on all surfaces. It is not necessary to cover the stovetop nor pour hot water on its surface.12
  4. Oven displays, knobs, hoods, surfaces etc.: These should all be cleaned well with an astringent cleanser. They need not be covered after cleaning.
  5. Refrigerators and freezers: These should be cleaned well with an astringent cleanser. All chametz food you are selling should be placed in a bag, fastened closed, and labeled “chametz” (or separated or clearly highlighted in some other way.) The shelves do not need to be covered after cleaning.
  6. Toaster/Toaster ovens: These should not be used during Pesach because they are too difficult to clean thoroughly.
  7. Microwave ovens: Since the walls of a microwave typically do not get very hot, it is sufficient to clean the microwave walls with an astringent cleanser. However, the glass plate on the bottom does usually become hot, so if your microwave has a glass plate, clean it with a cleanser and do not put food directly on the glass plate without a plate or bowl. Alternatively, you can cover the plate with two layers of plastic wrap. You do not need to boil water inside the microwave to kosher it.13
  8. Dishwashers: Run one regular full cycle while the dishwasher is empty with dishwasher detergent as you normally would.14
  9. Crockpots used for Chametz: These should not be used because they are difficult, if not impossible, to clean and to kosher.15
  10. Blenders and juicers: These may be used on Pesach if they are washed as usual.16
  11. Coffee makers and tea pots: These may be cleaned well and used on Pesach (assuming they were not used to cook any of the 5 grains.)
  12. Hot water urns: These may be cleaned inside and out with soap and used for Pesach.17
  13. Standing Mixers: If used for bread/chametz dough, these generally should not be used for Pesach because it is ordinarily too difficult to clean them properly.18
  14. Sinks, faucets, valves, handles, countertops, cabinet shelves, kitchen tables, bars, and other similar kitchen surfaces: These should also be cleaned well with an astringent cleanser. Kitchen surfaces need not be covered after cleaning. Sinks do not require an insert.19
  15. Hot plates and “platas”: Clean these well with astringent cleanser and best to cover with two layers of foil.20 If one used the hot plate without foil on Pesach, one need not be concerned about any kashrut ramifications.21
  16. Barbeque Grills: Clean all areas well, especially the grill and hood, and surrounding areas, with astringent cleaner. Clear out ashes and check for and remove any breadcrumbs. Burn out grill by turning up fire to highest temperature with the hood closed for about 10 minutes.

Kitchen Utensils, Cookware, and Tableware

  1. If a person has the means and desire to purchase separate pots, pans, dishes and utensils for Pesach, it is commendable. However, it is generally unnecessary to purchase new kitchen utensils for Pesach. The following methods to kosher your kitchen items are halachically sound and relatively quick and simple.
  2. Utensils, bakeware, and cookware used with HOT chametz:
  3. General Principles:

To prepare utensils for koshering: clean utensils well with soap. Inspect for food particles. For items koshered by hagalah (liquid) method, preferably wait 24 hours from last use with hot chametz.22 Items koshered by any libun (dry heat) method (chamur or kal)23 do not require a 24-hour waiting period.24

Then, for:

  1. Metal or stainless-steel utensils (forks, spoons, knives, etc.): Place in a clean pot (preferably a pot that was previously koshered for Pesach) of boiling water for about 10 seconds. To make things easier, you can (carefully!) dump all the utensils in at one time and move them around (carefully!) with a (koshered for Pesach) long, clean utensil in such a way that water touches all parts of the metal utensils. If the handles of the metal utensils are from a different material, it does not change the procedure.
  2. Pots that are used with liquid: Fill with water and bring to a boil. Kosher the lid by placing it on the boiling pot. Alternatively, if the pots and/or covers are heat resistant,25 you can place them into a hot oven at the temperature it is normally used at (or the oven’s highest temperature if the cookware is heat resistant at that temperature), until they become very hot, which usually takes about 2-5 minutes.26
  3. Pans: The easiest way to kosher a small pan is to hold it on each side, one at a time, over a flame for about 30 seconds.27 Heat resistant pans that are used in the oven may also be placed in the oven at the temperature it is normally used at until it gets very hot, which usually takes about 2-5 minutes.28 Non-stick pans may be koshered in this manner as well.
  4. Glassware/plasticware/glazed stoneware/Pyrex/ and other similar cook/bakeware, if heat resistant, may be koshered in an oven at the temperature it is normally used at (or the oven’s highest temperature if the cookware is heat resistant at that temperature) until it gets very hot, which usually takes about 2-5 minutes.29
  5. Utensils, pans, bowls, and tableware used ONLY for COLD FOOD OR LIQUID, even for chametz: These may be used after washing thoroughly.30
  6. Cutting boards (plastic or wood): Clean very well with soap and water. If there are crevices that cannot be cleaned, it is best to buy a special cutting board for Pesach.
  7. You may use your regular table linens and hand towels/cloth napkins on Pesach as you do during the year, if you clean/wash them with detergent in a washing machine.31
  8. For safety reasons, one should be careful not to expose utensils containing plastic or other potentially flammable materials to very hot temperatures (as with a hot oven or flame) for longer than necessary, so they do not create a fire hazard or become damaged. Most utensils that fall into this category are not normally exposed to raw fire, heat or a heating element (i.e they are not a ‘Kli Rishon’ – a ‘primary vessel’ used for food on the fire or heating element) and as such, if necessary, one may kosher these utensils for Pesach by cleaning them thoroughly with soap and hot water, using a non-chometz sponge.32

Kashering During Pesach

According to Ashkenazic custom, a utensil that must be koshered during Pesach33 may be koshered only via libun ([light or complete] burning)34 and not via hagalah (boiling water method.)35 The custom of Sefardim is to kosher utensils on Pesach via either libun or hagalah.36

Notes

  1. S”A YD 121:2

    ↩

  2. “k’boleo kach polto” (S”A YD 69:4, OC 451:5.)

    ↩

  3. S”A OC 451:4.

    ↩

  4. Rama OC 451:4. Many opinions hold that the temperature required to achieve libun kal is “yad soledet bo”, (120-170 degrees.) See Sma”g Mitzvah 145, Sefer Hatruma in the name of Ri Hazaken, Ran Avoda Zara 33b, Mordechai ibid, Shu”t Re’em 1:43, Magen Avraham OC 451:27, Taz OC 451:8, Pri Chadash OC 451:4-5, S"A HaRav OC 451:10 etc.

    ↩

  5. Mishbitzot Zahav OC 452:4 and MB 451:30. One difference is that one should preferably wait 24 hours before hechsher via hagalah which is not necessary with libin kal (or libin chamur.) See below 5:3.

    ↩

  6. S”A OC 451:3.

    ↩

  7. Heard in the name of many Poskim including HaRav Yaakov Kaminetsky zt’l, HaRav Aharon Kotler zt’l and HaRav YD Soloveitchik zt’l. This is also the opinion of HaRav SZ Auerbach zt’l in Halichot Shlomo 3:4 and Shu”t Minchat Shlomo 2:51. Also, see note above regarding libun. It is unnecessary to scrub the oven clean. Moreover, it is not advisable to use a blow torch, which is dangerous (and would therefore present a much more serious halachic concern regarding safety. “V’nishmartem meod l’Nafshoteichem!” - “Safeguard your lives!” (Devarim 4:15)) See Kovetz Halachos of HaRav Shmuel Kaminetsky Shlit’a (Kovetz Halachot etc.) Dinei Hagalot V’Kashrut Hamitbach 23:28-29.

    ↩

  8. Many Poskim view chametz before Pesach as ‘heteira bala,’ (see Avoda Zara 76a, Tosefot Chulin 8a & 108b, Magid Mishna

    Chametz U’Matzah 5:23, MB 451:32) and/or an issur gavra (see above note to 3:6e in the name of Chidushei Maharshdam, Sidur Pesach Kihilchato, Chiddushei Rabbeinu Chaim and the Ohr Sameach) and therefore deem it sufficient to use the libun kal (non-self-cleaning) method and do not require the more stringent libun gamur (self-cleaning) method. See S”A OC 451 and Maamar Mordechai ibid. 11, Mor U’ketzia 4, Pri Megadim 12, MB 34, AH 14. Also see Kovetz Halachot etc.

    ↩

  9. This is certainly enough time for the oven to burn out its chametz contents. See Sefer Kovetz Halachot etc., Yalkut Yosef 3:360. Also see MB 451:34 AH ibid 14.

    ↩

  10. While its self-cleaning mode might be the preferred halachic koshering method for an oven, this feature has many potential hazards which one must consider before deciding to use it. Among these concerns are: fire hazards, carbon monoxide poisoning and other toxic fumes, all of which are very dangerous for both humans (especially children) and animals. One should never leave an oven undergoing a self-cleaning cycle unattended. (“4 Reasons to Avoid Your Self-Cleaning Oven Feature”, (learn.compactappliance.com, 2015.)

    ↩

  11. See note above regarding Libun.

    ↩

  12. Since heat of the fire is what caused the chametz food to become injected into the surface of the stovetop, one would seemingly need the same heat to get it out. However, a stovetop is not like an oven. Even though it can sometimes get very hot, food is not intentionally cooked directly on the smooth stovetop. This should classify it like a countertop (addressed below 5:2n), so the reasons for leniency regarding a countertop would also apply to the stovetop. Another issue is that covering a stove with foil and/or pouring boiling water on it with or without a red-hot stone, etc., can be dangerous and/or can cause damage to the oven or kitchen, very appropriate matters to consider with a halachic authority before using these kinds of koshering methods.

    ↩

  13. Heard from a well-known Posek.

    ↩

  14. This works for hechsher because it is kiboleo kach polto and because the soap is pogeim (ligamrei.) Alternatively, it can be argued that since after 24 hours the dishwasher becomes notein taam lifgam and only requires hechsher midrabanan, we can therefore be lenient because of several factors including: a dishwasher is at worst an iruy kli rishon in a utensil, and/or the soap is always pogeim (ligamrei), and/or the chametz is always batel in the water, and/or our keilim today do not absorb taste. See below regarding countertops 5:2n and glassware etc. 5:3bV.

    ↩

  15. My experience is that a crockpot is one of the few utensils nowadays that potentially absorbs taste like a ‘Kli Cheres’ (pottery.) This could be the result of a combination of factors, including that the food sits in the ceramic pot for many hours each time it is used. However, if the ceramic insert is coated with a non-porous glass-like material, bidieved it would not necessarily have a din of a ‘Kli Cheres’, so each situation needs to be evaluated individually.

    ↩

  16. Per S”A OC 451:22. See note below regarding flammable materials.

    ↩

  17. There is no concern regarding ‘zeiah’ (S”A YD 92:8) with kettles and urns because the circumstances necessary to transfer taste through zeiah are numerous and unlikely to occur (See S”A ibid etc.)

    ↩

  18. If one can be certain that no dough remains within the crevices, it can be used after thoroughly washing with soap and water.

    ↩

  19. We can halachically conclude that there is no requirement to kosher these surfaces because:

    After 24 hours of nonuse with hot chametz, the surface no longer has the taste of chametz embedded in it, as we assume the taste becomes taam pagum (spoiled/weak/inedible.) There is a very strong case to be made that even according to the stringent opinion regarding notein taam lifgam on Pesach would not apply to items that absorbed chametz before Pesach. (Some of the below reasons are relevant to this issue; also, for example, see S”A & Rama OC 447:2 & 447:10, Chok Yaakov 447:11, MB 447:98,99, AH OC 447:21, Shu”t Besamim Rosh, Shu”t Dvar Moshe 29, etc. Also see Yabia Omer OC 8:43:1 & 10:35:18, Chazon Ish OC 119:12,14.)

    Nonetheless, by rabbinical injunction, one may not use a utensil even 24-hours after its last use with ‘issur’, because of the fear that one may inadvertently use it within 24 hours (Avoda Zara 76a S”A YD 122:2), and therefore one must normally kosher such a utensil with heat before being allowed to cook with it again. However, a strong case can be made that this prohibition only applies to utensils and pots/pans used for cooking, as opposed to stovetops/countertops/sinks. Some reasons for this are:

    (1) The Sages only prohibited using a utensil/pot (kedeira) after 24 hours, excluding stovetops/countertops/sinks which are not considered utensils/pot[s (see Avoda Zara 76a and Rishonim there.)

    (2) One does not cook on the stovetop/countertop/sink, so they are not considered primary vessels (Kli Rishon), in which case they are not subject to this rabbinical injunction (see S”A YD 105:2. Also, see Rama YD 68:10 regarding Iruy Kli Rishon which is only applied to food, not vessels or non-food items.)

    (3) The taste in the surfaces is considered ‘hetera bala’ (taste that is permissible since it is before Pesach) and ‘nat bar nat’ (a weakened, indirect taste through the medium of the surface) and therefore is not prohibited. See Chazon Ish OC 119:12,14, Yabia Omer OC 8:43:1 & 10:35:18.

    (4) The stovetop/countertop/sink is mostly used for cold or warm items and therefore not subject to this rabbinical injunction (‘rov tashmisho.’ See S”A and Rama YD 451:6. Also see AH OC 501:18, Chayei Adam 125:3.)

    (5) There is a sound opinion that all modern kitchen surfaces nowadays are not porous and do not absorb taste (based upon tested experience (anan sahdei) – see “Hamaayan” 5773 based on scientific testing. See S”A YD 99:7 & 122:5, Shu”t Rama 54. Also see S’dei Chemed, Asifat Dinim 5:21. Shu”t Radbaz 3:844. Also see Sefer Hilchot Pesach (RS Eider) II A 2: 3. Also see Megilat Sefer YD 96:16 - that HaRav SZ Auerbach zt’l frequently used this reason as a ‘tziruf l’hatir’ (an added reason for leniency), which is precisely the way we are using it here. Also see the excellent article on yeshiva.org by Rabbi Yitzchak Dvir, “Bliat Keilim Biyameinu,” where he brings many powerful proofs from Rishonim and Achronim and logical arguments to support the notion that many of our utensils today are either not bolea at all or only bolea a minute amount of taam.

    Additionally, by cleaning the surfaces with astringent cleansers, one further injects severely negative taste (taam pagum l’gamrei) into the stovetop/countertop/sink which adds another layer of negative taste to the surface. (See sources for anan sahadei above.)

    Even though some guides bring S”A OC 451:20 as a source requiring the koshering of countertops via iruy kli rishon, it is a very different case (see S”A ibid) and the S”A essentially holds that koshering is unnecessary in that case as well (see Kaf Hachaim 451:194.)

    Furthermore, one must also consider that covering, pouring boiling hot water, and/or handling red-hot stones to kosher stovetops/countertops/sinks is very dangerous and/or can potentially cause costly damage, so it can be argued that one would not be obligated to kosher the items even if the injunction applied to these surfaces.

    Also, since this involves a rabbinical issue (gezeira atu bat yoma or notein taam lifgam bikeilim or nat bar nat or mashehu) we can be lenient (safek d’rabbanan l’kula per Igrot Moshe EH 4:7 and Chazon Ovadia, Pesach 2003, etc.) So, in conclusion, when evaluating whether countertops and other kitchen surfaces require conventional koshering, there are several factors that strongly support a more lenient approach to the matter.

    ↩

  20. This is because some of the reasons for leniency concerning countertops etc. may not apply to a hotplate because food is cooked/warmed directly on the hotplate. Therefore, it is best to cover it with 2 layers of foil (if you do not put food directly on the hot plate, one layer will suffice per Rama YD 92:8 and 93 and Shach 105:22.)

    ↩

  21. Because some of the reasons mentioned above concerning countertops and kitchen surfaces apply to a hotplate surface as well.

    ↩

  22. S”A OC 452:1 and MB there. Also see Chazon Ish OC 119:12,14, Yabia Omer OC 8:43:1 & 10:35:18.

    ↩

  23. See above 5:1.

    ↩

  24. See Darkei Moshe 121:15, Rama OC 452:4 and MB 33.

    ↩

  25. If the utensil is not completely heat resistant, one can kosher it via a shorter amount of time (based on Tzitz Eliezer 10:2.) The same would be applicable to the following examples of pans and glassware etc. (5:3b:IV,V.)

    ↩

  26. This would accomplish “libun kal” which is the equivalent of haagala per Mishbitzot Zahav OC 452:4 and MB 451:30. According to the notes above regarding libun kal, the pot only needs to reach the temperature of “yad soledet bo” on all its surfaces, so once the entire utensil becomes very hot to the touch, it is considered koshered for Pesach purposes. We estimate the time it takes to reach “yad soledet bo on all surfaces to be “usually…2-5 minutes” but it may reach that temperature in more or less time.

    ↩

  27. This would accomplish “libun gamur”; however, halachically, libun gamur is unnecessary for a pan, so less time is sufficient (see S”A YD 121:4 and OC 451:11.)

    ↩

  28. See note above regarding pots.

    ↩

  29. See Shu”t Maseit Binyomin 94, Mishpetei Uziel 8:43, Knesset Hagedola YD 121:20, Mor Uketzia OC 451, Mishbetzot Zahav OC 451:31, Tzitz Eliezer 10:2, Chelkat Yaakov 2:163, Sridei Eish 2:160, Minchat Yitzchak 3:67, HaRav YE Henkin zt’l in Am Hatorah 1:10, Seridei Aish 2:160, Yalkut Yosef OC 451: 38. As noted regarding countertops, if 24 hours have elapsed since the last hot chametz use before koshering, the argument for leniency is even stronger because of safek d’rabbanan l’kula. See Igrot Moshe EH 4:7 and Chazon Ovadia, Pesach 2003 etc. See Darkei Moshe OC 451:19 and and Taz ibid and Kenesset Hagedola YD 121:25 that the universal opinion is that utensils that are smooth like glass can be koshered before Pesach. Also, see note above regarding pots.

    ↩

  30. Since there is no heat involved with their chametz use, the item is kosher for Pesach once washed clean. See S”A OC 451:22.

    ↩

  31. Magen Avraham OC 442:19, Igrot Moshe OC 4:106.

    ↩

  32. Despite S”A OC 501:1; see Shu”t Magen HaElef 452:3. Also, these utensils are not normally used directly with a heat source (i.e. they are not a kli rishon) and therefore do not require koshering with intense heat (per S”A YD 105:2.) See above note regarding countertops, as most of those reasons for leniency apply in this case as well, such as: ‘rov tashmisho’, kli sheini, anan sahdei, taam pagum l’gamrei, that the gezeira atu bat yoma is limited, and safek d’rabbanan l’kula. If needed, this leniency would apply to any utensil not typically used directly with a heat source.

    ↩

  33. For example, if the utensil was used for hot chametz food during the year and was not koshered before Pesach, or if it was used with hot chametz on Pesach.

    ↩

  34. See above in this chapter Principles. In such a case, the item can be koshered in a hot oven (libun kal.) See above for koshering procedures for various utensils.

    ↩

  35. Because there is an Ashkenazic custom not to rely on leniencies such as notein taam lifgam or bitul, even in a case of “nat bar nat’”on Pesach. See Rama OC 447:10 and 451:1 and see Darkei Moshe 451:2 based on Shu”t Rashba 1:262 that if we do not rely on these leniencies, the taam in the water will be reabsorbed into the utensil.

    ↩

  36. For hagalah, the utensil must be an aino ben yomo. See S”A OC 447:10 and 451:1.

    ↩