Hagalah

In Jewish law, Hagalah is a procedure performed in order to make fit for use cookware, bakeware, and utensils that were previously used with non-kosher foods in a way that caused the absorption of non-kosher flavors into the walls of the utensil.^[1]^[2]

Hagalah is also done in order to use utensils for dairy cooking after meat was cooked in them, and vice versa, or for using utensils during the Passover holiday after they were previously used with chametz (leavened products). Generally, the kashering is done in the same way that the non-kosher substance was absorbed into the walls of the utensil ("just as it absorbed, so it expels").^[1]

^ ^a ^b "01. Kashering Kelim – Peninei Halakha". Retrieved 2024-03-27. The Sages explained that when one cooks a non-kosher food in a pot, its taste is absorbed in the walls, and if one later cooks a kosher food in the same pot, the non-kosher taste will be released from the walls of the pot and enter the kosher food, rendering it forbidden. To remove the taste absorbed in the walls, the pot must be kashered in the same way that it absorbed the taste.
^ Doniel, Neustadt (2004). "Hagalah: A Koshering Process". Kashrut.com. Retrieved May 22, 2013.

[:0-1] "01. Kashering Kelim – Peninei Halakha". Retrieved 2024-03-27. The Sages explained that when one cooks a non-kosher food in a pot, its taste is absorbed in the walls, and if one later cooks a kosher food in the same pot, the non-kosher taste will be released from the walls of the pot and enter the kosher food, rendering it forbidden. To remove the taste absorbed in the walls, the pot must be kashered in the same way that it absorbed the taste.

[Neustadt-2] Doniel, Neustadt (2004). "Hagalah: A Koshering Process". Kashrut.com. Retrieved May 22, 2013.

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