Halacha » K’bolo Kach Polto – Beliot Come Out the Way They Go In

K’bolo Kach Polto – Beliot Come Out the Way They Go In

The Gemara (פסחים ל) writes regarding utensils that can be koshered, there is a rule k’bolo kach polto – whatever method was originally used to put the beliot in the utensil is the method necessary to remove the beliot. The Gemara explains that there are different levels of koshering a utensil. Cooking in water (hagala) removes beliot by pulling them back out. Just like the beliot went in through cooking, so too they can be pulled back out through cooking. Using fire to kosher (libun) actually burns up the beliot where they are. Libun is required when the beliot were absorbed through roasting. The beliot of roasted food is more entrenched in the utensil and cooking will only pull out some of the beliot, but not all. One must do libun instead, and through the libun all beliot in the utensil are burnt up where they are. For this reason, using libun to remove beliot that were absorbed through cooking would work, because libun burns up all beliot in a utensil. Hagala, however, would not remove beliot absorbed through fire because they are too entrenched to get pulled out, and must be burnt out.