The laws of Kashering vessels are complex and hence it should only be done by one which is expert in these laws.

One must be aware of the following details:

  1. Is the vessel made of a Kasherable material?
  2. How has the vessel been used? What form of Kashering is required for it? Libun? Hagalah?
  3. What must one do if the vessel is rusty?
  4. How does one do Libun?
  5. How does one do Hagalah?
  6. May the vessel be Ben Yomo?
  7. Must the vessel one is Kashering in be itself Kashered?
  8. How long must the vessels remain in the water by Hagalah?
  9. May many vessels be Kashered simultaneously?
  10. May one Kasher on Erev Pesach or Pesach?

A. What to do with Chametz vessels that one does not plan to Kasher:

Cleaning: All Chametz vessels which one does not desire to Kasher for Pesach, or is unable to Kasher them, are to be cleaned from Chametz. One is to scrub them and slightly rinse them down from any recognizable Chametz.

Putting them away: One is to hide the vessels in an area which he is not accustomed to enter into throughout the entire Pesach. Furthermore, it is proper to place the vessels in a room [or closet] which will be locked, and then hide the keys, in order to prevent any possibility of entering there during Pesach. Those which are accustomed to place the vessels in a very high area which is visible, have upon what to rely, although one who is stringent to hide them away from sight will be blessed.

Un-cleanable Chametz vessels: All vessels that are difficult to clean from Chametz are to be sold to a gentile and stored away as written above.


B. Buying new vessels:

New vessels which are bought from a gentile do not need to be Kashered. Hence all vessels which appear new may be bought from a gentile store or company. However vessels sold by a gentile individual from his home are not to be purchased


Do new pots and pans need to be Kashered today due to suspicion of them having been smeared with non-Kosher fats?

Many Poskim rule that there is no need to Kasher new pots or aluminum which had non-kosher fats smeared on them during manufacturing. However some are accustomed to be stringent. Practically the worldwide custom is to not require them to be Kashered. However in certain areas, such as Eretz Yisrael, many are accustomed to do so.


C. What form of Kashering does a vessel require-General rules?

*The below list only refers to the form of Kashering required for vessels made of Kasherbale materials. For a list of those materials that are Kasherable and those materials that are not Kasherable-see Halacha E! For a list of vessels and their specific Kashering Laws see Halacha F!

Chametz cooked in liquid in the vessel: All Kasherable material vessels that had Chametz cooked with liquids require Hagalah or Libun Kal.

Chametz baked without liquid in the vessel: All Kasherable material vessels that had Chametz baked in them [without liquids] require Libun Chamur.

Chametz soaked in the vessel: All Kasherable vessels which had Chametz soaked in liquid for 24 hours require Hagalah or Libun Kal.

Do pots which are used to cook in have the status of absorbing food through liquid, or the status of absorbing food directly? All pots that had food cooked inside with liquid have the status of absorbing food through liquid, even if the food burnt inside the pot, and thus it does not require Libun Chamur, as there is always some liquid found on the bottom of the pot.


D. What materials may be Kashered?

Earthenware pottery: Can only be koshered through placing it in an oven and heating it to the point that it can be reformed. Even if an earthenware dish was used for only cold Chametz, one should not place even cold Pesach foods on it. An earthenware oven can be Kashered through Libun Gamur. Examples of earthenware vessels that cannot be Kashered:Crockpot; Mugs.

Sundried clay vessels: Vessels made of sun dried, is Kasherable

Wood vessels: Is Kasherable so long as it does not contain cracks and the like. The custom is to Lechatchilah never use any wooden vessels which were used for flour consistently, even if one cleaned it and performed Hagalah. All wooden vessels may be sanded down and koshered.

Metal vessels: Are Kasherable. If the vessel absorbed the food through cooking in water, then it suffices for it to be heated to the point that its outside reaches the point of “Yad Soledes Bo”. This can be done by either using a torch [Libun Kal] or dipping it in boiling water [Hagalah]. If the vessel absorbed the food directly, without any liquid then it requires “Libun Gamur, which means that it must be heated until sparks begin to fly off from it, or until a layer of it peels off. This applies even Bedieved.

Glass vessels: The custom amongst Ashkenazic Jewry is not to Kasher for Pesach any glass vessels which have suspicion they may have absorbed Chametz. These vessels are not to be used for Pesach, and are rather to be put away with the Chametz vessels. [Sefardim however are lenient to allow using glass vessels even without Hagalah, so long as they have been washed and cleaned.]

Glass coated vessels: If the vessel is coated with glass on its inside, in the area where the food is placed, then it may not be Kashered. If it is coated with glass only on its outside, then if it is never commonly placed directly over a fire to cook in, such as silver vessels coated externally with glass, then it may be Kashered through Hagallah. If however it is not uncommon to use it to cook with over a fire, or even to occasionally heat food in it over a fire, then it may not be Kashered.

A vessel placed together using glue: Hagalah is invalid for such a vessel as the heat can easily ruin it and there is thus suspicion that to prevent this one will not heat the water enough for the Hagalah.

See the chart below for all of the following materials: Ceramic; Enamel; Marble; Plastic; Porcelain; Pyrex; Teflon.


 E. Practical list of items:

List of vessels and their Kashering status




Kasherable based on use

Baking Pan

Libun Chamor They are thus not Kasherable.

Burners of stove top

Libun Chamor


Cannot be Kashered


Cannot be Kashered


Iruiy Keli Rishon with Even Meluban


Cannot be Kashered unless made of metal, in which case needs Hagalah


Cannot be Kashered


Custom is not to Kasher for Pesach

Frying pan

If coated with enamel/Teflon may not be Kashered. If not coated may be Kashered based on use.


Cannot be Kashered

Grates of stove top

Libun Chamur






Libun Chamur

Kiddush Cup [silver or metal]



Best not to Kasher for Pesach; if Kasher needs sharpening and Hagalah


Dispute amongst Poskim if may be Kashered.

Pot [not coated with enamel]



Cannot be Kashered


Dispute amongst Poskim if may be Kashered.



Sink spout

Clean and wash

Sink [made of enamel/ceramic/glass/plastic]

Cannot be Kashered

Sink [made of metal]

Iruiy with even Meluban

Skewer for barbecue

Libun Gamor

Steel [including stainless steel]

Kasherable based on use

Stove top [enamel]

Cannot be Kashered

Stove top [stainless steel]

Iruiy Keli Rishon with Even Meluban


Cannot be Kashered

Toaster Oven

Do not Kasher. Sell to gentile and put away

Wood [without cracks]


Wood [with cracks]

Cannot be Kashered


Pots, Cutlery and Kitchenware


All forks, spoons and other cutlery made of Kasherable material, such as silver or stainless steel, are to be Kashered through Hagalah.



It is a Mitzvah Min Hamuvchar for all those which have the capability of doing so, to buy new knives for Pesach. However from the letter of the law doing Hagalah to them does suffice [and one may certainly rely on this if it is not so feasible for him to get new knives.] One must sharpen the blade prior to doing Hagalah in order to remove any rust he blade may contain. If the knife contains a handle and the blade is inserted into the handle then it cannot be koshered due to the inability to remove any Chametz from in between the crevices. Likewise if the blade is attached to the handle with glue it cannot be Kashered.



The custom is to Kasher cups through Hagalah. If one used the cup for a hot Pesach drink without previously Kashering it, the drink remains Kosher.  

Glass cups: Are not Kasherable.

May one Kasher a Kiddush cup that contains an upper lip? Yes, as the lip is external and there is thus no worry that Chametz entered inside.



Whether or not a pot may be Kashered is dependent on the material that it contains of-See previous Halacha E! If the pot is made of a Kasherable material, such as metal without a Teflon coating, then if it is used for cooking with liquid it requires Hagalah. 

Teflon/Enamel: If coated with enamel/Teflon then it may not be Kashered.

Do the handles of pots and pans need to be Kashered? From the letter of the law they do not need to be Kashered and certainly one need not worry of the cracks that they contain [which may have food on them]. Nevertheless one should clean it and do Hagalah to it, or do Iruiy Keli Rishon without needing a stone.

Do pot covers need Hagalah? Yes.


Frying pans and all pots used for frying:

If one used this pot to fry the food with a nice amount of oil, than by Kashering for Pesach the pan needs Hagalah. If however one fried food in it using very little oil, just enough so the food does not stick, then the pot needs Libun.

Teflon/Enamel: If coated with enamel/Teflon then it may not be Kashered.


Appliances and furniture

The stove:

The grates: Need Libun Chamur. If one cannot do Libbun Chamor, then clean very well and wrap the grates in thick aluminum that will last throughout Pesach.

Burners: Clean the burners and use toothpicks or needles to remove any dirt or food from within the gas holes of the burner. Afterwards, turn on the fire for some time to accomplish Libun Kal.

Stove top surface: One is to clean the stove surface well and then do Iruiy Keli Rishon to it. If the surface is made of non-Kasherable material, such as enamel, that it must be covered with aluminum.

Knobs: One is to clean the stove knobs very well, cover them or attach clean replacement knobs.

Covering all items: Practically the custom is that even after Kashering all the above items of the stove, one covers all the surfaces with aluminum.



From the letter of the law it requires Libun Chamur. If ones oven does not have self clean oven it is very difficult to accomplish Libun Chamur through using a blow torch, as the oven can break in the process. One is thus to buy a Pesach oven or alternatively Kasher it in the following way:

  1. Clean the oven well using a Chametz killing agency such as bleach or oven stain remover.
  2. Wait 24 hours prior to Kashering.
  3. Turn the oven on for a period of at least one hour to its highest temperature or blow torch the oven from the inside.
  4. After the Kashering process is complete one should cover the walls and floors with aluminum foil.


Self cleaning oven:

An oven with self cleaning mode reaches a temperature of 900° F and is equivalent to Libun Chamur. An oven with a “Continuous cleaning” cycle is not equivalent to Libbun Chamur, and hence the above mentioned method must be used.




If one is accustomed to place hot pots on his counter or table then the custom is to do Iruiy Keli Rishon with Even Meluban. However other surfaces on which one is not accustomed to place hot Chametz pots do not need to be koshered.

Covering the counter or table: If one covers his table or counter then from the letter of the law it does not need to be Kashered. Likewise if the counter or table has been Kashered it does not need to be covered. However the custom is to do both, to Kasher and cover the areas.  

The walls of the counter: They are to have Iruiy Keli Rishon performed and then covered.


Must one cover all kitchen surfaces such as tables, counters, cabinets, refrigerator shelves and the like?

From the letter of the law, once these areas have been properly cleaned and Kashered they may be used for all foods without any cover. However some Poskim rule that one is to cover the surfaces even after they are Kashered due to suspicion that perhaps they still contain actual Chametz that was not properly removed. Practically the widespread custom is to cover all items that contact food even after they have been cleaned and Kashered.



The actual sink: The Kashering of a sink is dependent on the material that it is made of. A metal sink can be Kashered through Iruiy Keli Rishon. Most sinks are made of Porcelain or enamel which are non-Kasherable materials and thus cannot be Kashered. Nevertheless, the custom is to do Iruiy Keli Rishon on such material sinks. One is then to insert a sink insert which will be used throughout Pesach.

The spout: The custom is to clean and wash the spouts of the sink as throughout the year they have been used with hands that are dirty from Chametz. [One is to pour boiling water of the spout, and leave it open with the hot water running.]

Knobs: Wash and clean.

The drain: Pour boiling water that contains bleach or Drano down the drain.

Metal strainer: Iruiy Keli Rishon.

Using the hot water on Pesach: It is advised not to use hot water that is over Yad Soledes [110° F] on Pesach, in a sink that is not Kasherable, as one can possibly Treif up the vessels in the sink through doing so. Thus one should not turn on the hot water to the point of Yad Soledes and is likewise not to pour hot water into the sink. If the water is warm, below Yad Soledes, it may be poured into the sink. Likewise if the hot water of a pot was placed in a Keli Sheiyni, it may be poured into the sink even if it is still very hot.

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