My wife just cooked hot cheese sauce (in a milky pot), took it off the fire, added cold noodles (to make macaroni and cheese), and then put a pot cover on top – to retain warmth. I then noticed that it was a meaty pot cover (aino ben yomo) used for shabbos chicken soup.
I took off the cover and noticed that it was covered in condensation.
Is everything assur? What needs to be kashered? I remember hearing that pot covers are more stringent even by aino ben yomo – does that affect it here?
The lid of the pot needs to be kashered, because it has absorbed the ‘taste’ of the cheese sauce through the condensation. The pot, however, does not need to be kashered, and the food is also permitted.
Sources: The Rema (end of Yoreh De’ah 93) writes that the cover of a pot receives the din of ben yomo even though it is not a ben yomo, though he calls this a stringency without a reason. He is prepared to be lenient in places of loss, but writes that in cases of a cold lid on a hot pot, both are prohibited.
According to Shach (4), one can only permit the pot when the pot has 60 times the volume of the lid, which is unlikely for any normal pot. Taz, however (2) writes that one requires 60 times the “makom katzar” in the cover, meaning the small crevice at the centre of the lid that can’t be cleaned properly, and which contains food be’ein. Some rule like the Shach, and others like the Taz (see Chochmas Adam 46:3; Shaarei Teshuva, Orach Chaim 447:2; Peri Megadim 4; Pischei Teshuva 3 (ruling like Shach); Minchas Yaakov 84:22; Chavas Saas chiddushim 3; Yaavatz; Rabbi Akiva Eiger (like Taz).
In our case, a number of considerations should be taken into account:
1. The cover is for a pot for shabbos, and if the food is required for Shabbos, this would be a loss and would perhaps be sufficient to permit even according to Rema (see Peri Megadim).
2. The pot was off the fire for a while, and the temperature of the soup was not verified, so that it is possible that it was no yad soledes.
3. Aruch Hashulchan rules like the Taz, and adds that nowadays our covers do not have the “makom hakatzar” and are wide and flat, so that one does not have to be stringent.
4. Shach also mentions that one may be lenient if there is another senif.
Therefore, one can be lenient for the pot and food, but not for the lid.
[Thanks for Rabbi Yehuda Spitz for pointing out the sources for this question.]