Kashering Utensils for Pesach Use
The prohibition against eating chametz applies to chametz that is transferred from a utensil into a food item. For this reason, a utensil that was used for chametz may not be used for Pesach food items unless the utensil undergoes the proper kashering (method of making a utensil kosher) procedure. In this issue, we will focus on some of the principles of kashering as they relate to the laws of Pesach.
The Method of Kashering
The Mishna, Avodah Zarah 75b, states an important principle regarding kashering: if one wants to kasher utensils that were used for non-kosher food, the method of kashering depends on the normal use of that utensil. A utensil whose contact with non-kosher food is normally through a liquid medium (cooking) is kashered by hagalah (placing the utensil in boiling water). A utensil whose exposure to heat is normally without a liquid medium is kashered through libun (direct fire). The Gemara, Avodah Zarah 76b, describes this principle as k'bol'o kach polto, the manner in which the non-kosher food enters the utensil is the same manner in which it is expelled. The Gemara, Pesachim 30b, uses the term k'bol'o kach polto to describe the methods of kashering utensils for Pesach that were previously used for chametz.
What this means practically is that utensils that absorbed chametz directly without a liquid medium (e.g. a baking sheet) must be kashered through direct fire and placing them in boiling water is insufficient. Many modern utensils cannot withstand the intense heat that is produced through direct fire making kashering of these utensils a practical impossibility.
Nevertheless, the Gemara, Avodah Zarah 76a, provides a leniency regarding kashering that may be applicable to Pesach. The Gemara states that if the item that was absorbed into the utensil was permissible at the time of its absorption and later became prohibited while already absorbed in the utensil, one may kasher the utensil through hagalah (boiling water) even if the manner of absorption was through a non-liquid medium. This principle is known as heteirah balah (it was absorbed as a permissible item).
There is a dispute among the Rishonim regarding the applicability of the heteirah balah principle to Pesach. Tosafot, Pesachim 30b, s.v. V'Hilcheta, note that the absorption of chametz prior to Pesach might be considered a form of heteirah balah, (since at the time of absorption chametz is not prohibited) and therefore, utensils can be kashered through boiling water even if they absorbed chametz directly. Ra'avad, Avodah Zarah 76a, s.v. Rav Ashi, states definitively that chametz is considered heteirah balah. Maggid Mishneh, Hilchot Chametz UMatzah 5:23, infers from Rambam that Rambam also considers chametz to be heteirah balah. However, many Rishonim disagree with the premise that chametz is considered heteirah balah. Ramban, Avodah Zarah 76a, s.v. Rav Ashi, explains that vis-א-vis Pesach, chametz is never considered a permissible item. Although, it is permissible to eat chametz throughout the year, the chametz status always exists. The principle of heteirah balah only applies to an item that undergoes a status change from being completely permissible to becoming prohibited while it is absorbed in the utensil. [The Gemara's example of heteirah balah is the meat of a korban that is absorbed into a utensil and while it is in the utensil becomes notar (leftover meat), which is prohibited.] Therefore, there are no grounds to perform hagalah on a utensil that absorbed chametz through a non-liquid medium.
Shulchan Aruch, Orach Chaim 451:4, codifies the opinion of Ramban that one must use direct fire to remove chametz that was absorbed through a non-liquid medium. Nevertheless, Mishna Berurah 451:28, notes that the opinion that chametz is considered heteirah balah should not be discounted completely and may be used in situations where there are other reasons to permit hagalah.
Performing a Proper Hagalah
Rabbeinu Asher, Avodah Zarah 5:35, notes an interesting dilemma regarding hagalah on non-kosher utensils. If one places a non-kosher utensil into a pot of boiling water, the non-kosher food that is currently absorbed in the utensil will enter into the water and the water will become non-kosher. The non-kosher water will then enter the utensil and the utensil will once again become non-kosher. Rabbeinu Asher presents two solutions to this problem. One option is to kasher the utensil in a pot of water whose volume is more than sixty times the volume of the utensil. This will ensure that any non-kosher food that enters the water will become nullified in the water and will not render the utensil or the pot non-kosher. Alternatively, one can wait until the non-kosher utensil was not used for twenty-four hours. Food that is absorbed in a utensil for more than twenty-four hours imparts an undesirable taste (noten ta'am l'fegam) and does not render the water non-kosher. Therefore, one can kasher a utensil that was not used in the last twenty-four hours even if the volume ratio of the water to the utensil is less than sixty.
Rabbeinu Asher does note that if one desires to kasher a utensil for Pesach use prior to Pesach, there is no need to employ either solution. He explains that the chametz that is absorbed in the utensil is considered a permissible item before Pesach. When the chametz enters the water, it is considered a secondary taste transfer, going from the chametz to the utensil, and then from the utensil to the water. As we discussed in a previous issue, there is a distinction between a secondary taste transfer of a permissible item and a secondary taste transfer of a prohibited item. The taste transfer of a prohibited item remains prohibited even after multiple transfers, whereas the taste transfer of a permissible item does not impart its status to the new item. A secondary taste transfer of a permissible item is colloquially known as nat bar nat d'heteirah.
Based on nat bar nat d'heteirah, Rabbeinu Asher permits kashering a utensil that was used for chametz in the last twenty-four hours in a pot that contains less than sixty times the volume of the utensil. There is no concern that the chametz in the utensil will render the water chametz because the water only absorbs a secondary taste transfer of chametz, a permissible item.
Rabbeinu Asher's ruling is codified by Shulchan Aruch, Orach Chaim 452:1 Many Acharonim question Shulchan Aruch's position. Rabbeinu Asher's ruling is predicated on the assumption that chametz is considered a permissible item before Pesach. Yet, Shulchan Aruch rules in accordance with Ramban that one cannot rely on the principle of heteirah balah in allowing hagalah on a utensil that absorbed chametz through a non-liquid medium. Ramban's position is predicated on the assumption that chametz is considered a prohibited item even before Pesach. How then can Shulchan Aruch codify both the opinion of Rabbeinu Asher and Ramban? R. Chizkiyah Da-Silva, P'ri Chadash, Orach Chaim 452:1, notes that the apparent internal contradiction in Shulchan Aruch can also be found within the rulings of Rabbeinu Asher. Rabbeinu Asher, in a responsum (14:1), specifically requires direct fire for the kashering of utensils that absorbed chametz through a non-liquid medium.
The Vilna Gaon, Orach Chaim 452:1, is of the opinion that the two issues are interrelated. Either one is of the opinion that chametz before Pesach is a permissible item and one may rely on both of the aforementioned leniencies or one is of the opinion that chametz before Pesach is a prohibited item and one may not rely on either of the leniencies. Based on this reasoning, Mishna Berurah (452:13, and Bi'ur Halacha 452:1, s.v. K'dei) rules that one should be stringent on both issues. Therefore, one should not perform hagalah on utensils unless they either haven't been used for chametz in the last twenty-four hours or the volume ratio of the water to the utensil is more than sixty.
R. Avraham Y. Karelitz, Chazon Ish, Orach Chaim 119:14, disagrees with Mishna Berurah's assertion. He claims that the principles of heteirah balah and nat bar nat d'heteirah have two different standards of what is considered a permissible item. Chametz prior to Pesach is considered a permissible item for the principle of nat bar nat d'heteirah, thus permitting one to kasher a utensil that was used for chametz in the last twenty-four hours in a pot that contains less than sixty times the volume of the utensil. However, it is not considered a permissible item for the purpose of heteirah balah, thus requiring direct fire in order to kasher items that absorbed chametz through a non-liquid medium.