Forms of Kashering

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Forms of Kashering:

The Torah taught us a great rule “Kebolo Kach Polto”; the same way the Issur has entered into the vessel is the same way that it can be removed. There are a thus number of different forms of Kashering that exist, each pertaining to the vessels quality of use with food. How each vessel is to be Kashered, and what level of Kashering it needs, is determined based on its past use.

The following are the different levels and forms of Kashering:

  1. Libun Chamor
  2. Libun Kal
  3. Hagala
  4. Iruiy Keli Rishon with Even Meluban
  5. Miluiy Veiruiy
  6. Hadacha


Libun Chamor/Gamur:[1]

What is it? Libun Chamor is defined as torching the vessel until sparks fly from it, or alternatively, until a sheet of its metal peels off. [Practically, today the above does not occur to the metal, as it is much denser than in previous times. Accordingly, the following other signs should be used today: 1) If the metal becomes red it is considered to have reached Libun Chamor. 2) In degrees, if one heats the item until 400 degrees Celsius, it is considered to have reached Libun Chamor.[2]]

When is it required:[3] All Kasherable material vessels that had Chametz baked in them without liquids are disputed if they require Libun Chamur or Hagala and practically we rule that they need Libun Chamur.[4]

If Libun Chamor was not performed:[5] In all cases that Libun Chamor is required for Kashering for Pesach, and one only did Libun Kal or Hagala, then one may be lenient in a time of great loss or Simchas Yom Tov in a case that one already used the pot for cooking. However, by other Issurim one may never be lenient.

Libun Chamor on Chol Hamoed Pesach:[6] One may Kasher a vessel through Libun even on Pesach.

Ben Yomo:[7] Libun Chamur may be performed onto a Ben Yomo vessel, even initially.


Self cleaning oven:

An oven with self cleaning mode reaches a temperature of 900° F and is thus equivalent to Libun Chamur. This helps to perform Libun Chamor to itself, as well as to all Kasherable utensils that are placed in it while on a self-cleaning cycle. An oven with a “Continuous cleaning” cycle does not reach this level of heat and is not equivalent to Libun Chamur.



Libun Kal:

Libun Kal is defined as torching the vessel on the inside[8] until its opposite side becomes Yad Soledes.[9] When burning Chametz from a rusty area or crack, the custom is to do so until the point that a piece of straw would burn if it were to be placed on other side.[10] [Placing a pot on a flame until the pot reaches Yad Soledes is not defined as Libun Kal, as the flame must be placed inside the pot, and pas sthrough every part of the inside.[11]]

When is it required: Libun Kal is as an alternative Kashering method to Hagala.[12] In certain cases, Hagala does not help, and thus Libun Kal must be used. For example, if a vessel contains cracks or rusty areas that cannot be cleaned, then those areas must have Libun Kal performed to them to burn any Chametz that they may contain.[13] Likewise, if a vessel is so long that part of its middle area will not enter the pot, then one may do Libun Kal to that area.[14] It is not valid to perform Libun Kal to a vessel which requires Libun Chamor, as explained in A.[15]

Ben Yomo:[16] Libun Kal may be performed even onto a Ben Yomo vessel, even initially.



Hagala is defined as entering the vessel into a pot of boiling water. The detailed laws of Hagala are explained in Halacha 10!

When is it required:[17] All Kasherable material vessels that had Chametz cooked in them with liquids require Hagala [or Libun Kal]. It is not valid to perform Hagala to a vessel which requires Libun Chamor.


Iruiy Keli Rishon with Even Meluban:[18]

Iruiy Keli Rishon with Even Meluban refers to pouring a direct[19] stream of hot water from a Keli Rishon[20] onto an item [i.e. Iruiy Keli Rishon], and then passing a red-hot stone or red-hot metal [i.e. Even Meluban] throughout the entire[21] vessel, hence causing the water to boil.[22] Bedieved, even if the water was poured from a Keli Sheiyni it is valid if it had the Even Meluban pass through and boil the water in the entire vessel.[23] Vessels that have protruding areas that prevent passing the stone over them, are invalid for this form of Kashering.[24] The detailed laws of Hagala, which apply likewise to Iruiy Keli Rishon with Even Meluban, are explained in Halacha 10!

When is it required:[25] This form of Kashering is a valid alternative of Hagala for all vessels that require Hagala, but cannot have Hagala done to them, such as they are too large and thus cannot fit into a pot, or are immobile [such as a counter.] Nonetheless, in all cases that it is possible to perform Hagala within a Keli Rishon, then one must do so and may not rely on Iruiy Keli Rishon and Even Meluban.[26]


Practical ways of performing Iruiy Keli Rishon with Even meluban:

Using an iron: A hot iron which causes the water to boil may be used as an Even Meluban. Hence, when Kashering through Iruiy with Even Meluban one is to pour hot water onto the surface and then pass the hot iron throughout the entire surface of that item, hence causing the water to boil. When doing so, one must observe when the iron has lost its power of heat to be able to boil the water, and consequently reheat the iron to its boiling power, and continue from where he left off.

Using a water boiler “Kumkum”:[27] Water which is poured from an electric water boiler [“Kumkum”], while the heating coils are still on and the water is boiling, is considered like both Iruiy and Even Meluban, and hence when pouring from such a vessel there is no need to pass over the surface using a red-hot stone or metal. [This, however, can only be achieved while the boiler is still plugged in and attached to the heating element.]

Must the Even Meluban contact every part of the item being Kashered?

Yes.[28] However, some Poskim[29] rule that it suffices for the boiling water which hit the stone to spread to every area of the item, and it is not necessary that the actual stone contact all the areas. Thus, protrusions and the like which prevent placing the stone directly on them is only problematic if the water which hits the stone is unable to reach those areas. Whatever the case, using a water Kumkum while the water is still boiling with the heating element still on, can read all areas of the vessel, and be valid according to all.


Miluiy Veiruiy Shalosh Peamim:[30]

This refers to soaking water in the vessel for 24 hours, three times. One fills up the vessel till it’s very top with even cold water, and lets it sit there for 24 hours or more, and then spills out the water. One does this for a total of three times, even inconsecutively.

When is it required: All Kasherable vessels which had Chametz soaked in liquid for 24 hours require Hagala, or have the alternative option of having water soaked in them three times for 24 hours. This form of Kashering is valid even for earthenware vessels which absorbed cold Chametz through having it soak in them for 24 hours. This form of Kashering is not a valid alternative for any of the previously mentioned forms of Kashering.



This refers to Kashering through cleaning the vessel very well in order to get rid of any surface residue. It may be cleaned even with even cold water. One is to use soap and a scrub to remove the food and is then to wash the vessel in water to remove the dirt. Once it is clean of all food residue, Hadacha is completed.

When is it required: Those vessels that were only used for cold Chametz foods, and never had Chametz soaked in them for 24 hours, are to be Kashered through Hadacha. Once they have been thoroughly cleaned, one may use them on Pesach for even hot foods.[32] Likewise, Hadacha is valid for allowing one to place cold Pesach foods on a Chametz vessel, even if it requires Kashering and was not Kashered.[33] Nonetheless, in the latter case, this may only be done on mere occasion, as explained in Halacha 2!

Earthenware: If an earthenware dish was used for only cold Chametz, although it is permitted from the letter of the law to be used even with hot foods, the custom is not place even cold Pesach foods on it during Pesach.[34] Certainly this applies if the earthenware dish was used for hot Chametz foods.[35]


[1] Admur 451:13

[2] See Ohel Yaakov Hagalas Keilim p. 24-25 for a discussion on this matter

[3] Admur 451:13; Michaber Y.D. 121:4

Regarding Basar Bechalav: A [non-earthenware] pot which absorbed meat and then milk or vice versa never needs Libun Chamor. [Admur 451:13 in gloss; Shach 121:7] However, an earthenware oven requires Libun Chamur. [Admur 494:16; 461:1] An earthenware pot cannot be Kashered. [Admur 451:9]

[4] Background: If the vessel absorbed the Chametz directly, without any liquid involved, such as by a baking pan, then a dispute exists as to what type of Kashering it needs. Some say that even Hagala [placing it in boiling water] suffices. Their reasoning is because Chametz before Peach is permitted, and therefore does not require such extreme heat to be Kashered. However, other Poskim rule that 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. Practically, we rule like the latter opinion, even bedieved [such as that one already used the pot to cook in] that it needs libun gamur. [Admur ibid]

[5] Admur ibid; See Rama 451:4; M”B 451:32

[6] Admur 452:19

[7] See Admur 452:19

[8] Admur 4651:10 “Fill the inside with coals”; Igros Kodesh Rebbe Rashab 5:226; See Tosafus Avoda Zara 33b; Smag Lo Sasei 148; Sefer Hateruma 161; Hagahos Maimanis Machalos Assuros 11:15; Or Zarua Avoda Zara 2:169; Hagahos Ashri 2:22

[9] Admur 451:10 and 37; See Igros Kodesh Rebbe Rashab 5:226; Vetzaruch Iyun from 451:44 that implies the other side must have straw burn on it

[10] Admur 451:16 and 19 and 38

[11] See Admur ibid; Piskeiy Teshuvos 451:18

[12] See Admur 451:10 and 37; Taz 451:8; Rama 451:4; Igros Kodesh Rashab 5:226; Ohel Yaakov Hagalas Keilim p. 27 who writes that Libun Kal is better than Hagalah; Nitei Gavriel 65:13

[13] Admur 451:16 and 19 and 38

[14] Admur 451:37

[15] Admur 451:13; Rama 451:4; M”B 451:32

[16] See Admur 452:19

[17] Admur 451:13-14

[18] Admur 451:27-31; 58; See Piskeiy Teshuvos 451:30

[19] Admur 451:29-30; This refers to “Lo Nifsak Hakiluach” in its Hebrew term and means that the water was still attached to the Keli Rishon pot by the time it hit the surface of the vessel. See next footnote for the full details of this requirement.

[20] It is disputed amongst Poskim as to whether one must pour from a Keli Rishon when using Even Meluban, as in any event the stone will re-boil the water, and hence should be valid even if the water is poured from a Keli Sheiyni or Nifsak Hakiluach. Practically, while the custom is to be lenient, initially it is proper to be stringent in all this. [Admur 451:30]

[21] Admur 451:27 “Al Pnei Kulah”

[22] Admur 451:27; See Q&A!

[23] Admur 451:30

[24] Admur 451:27

Other opinions: Some Poskim invalidate the use of Iruiy Keli Rishon with Even Meluban as an alternative for Hagala. [See M”B 451:51]

[25] Admur 451:27

[26] The reason: As some Poskim rule Iruiy with Even Meluban is not a valid alternative to Hagala. [Admur ibid]

[27] See Sefer Hakashrus [1 footnote 22] who compares this form of Kashering to Iruiy with Even Meluban. So also seems logical being that the coils inside the boiler are constantly boiling the water which is coming into contact with the item. It is hence just like placing an Even Meluban over the water, as the entire point of the Even Meluban is to heat it to the point of a Keli Rishon. [See Admur 451:27 and 30 that the entire purpose of the Even Meluban is to boil the water, and hence what difference does it make if it boils it from close or from far.]

[28] Admur 451:27

[29] M”B 451:53; Piskeiy Teshuvos 451:30

[30] Admur 451:60

[31] Admur 451:2; 43; Michaber Y.D. 121:1

[32] Admur 451:43

[33] Admur 451:2

[34] Admur 451:43

[35] Admur 451:2

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