Q&A from the Bais HaVaad Halacha Hotline

Foiled Pans

December 19, 2024

Q I’m staying at an Airbnb rental where cooking utensils, presumably nonkosher, are provided. May I bake in their pan if I line it with aluminum foil? Does it need tvilah?

A When a utensil is heated, it expels blios (absorbed tastes) from the foods that were previously cooked in it. But blios only transfer via a liquid medium. If two hot pots touch each other with no liquid at the contact point, no blios will transfer (Rama Y.D. 92:8).

You may line a nonkosher pan with foil and then bake in it. It is important to use multiple layers, as foil tears easily. Before lining the pan, ensure that it is completely clean and thoroughly dry. While some authorities permit a small amount of moisture (Chavas Da’as ibid. 20), others maintain that even a tiny amount transfers blios (Yad Yehuda ibid. 56).

If you discover after baking that some liquid leaked, the food is permitted, provided the pan hadn’t been used for nonkosher cooking during the past 24 hours. This renders the taste pagum (stale) and acceptable bedi’eved. But if you heated a davar charif (sharp item, like onions) in the pan, the food would be forbidden, because the sharpness restores the stale taste (Y.D. 103:6).

Lining a utensil to place a barrier between it and the food does not exempt it from tvilas keilim (Chut Shani, Tvilas Keilim p. 24). But in your case tvilah is not necessary at all, because the utensil is likely owned by a non-Jew (Y.D. 120:8). If the property and utensil are owned by a Jew, there may be room for leniency if tvilah isn’t possible (see Minchas Shlomo 2:68).