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Shabbat Parashat Ki Tavo 5771

Ask the Rabbi: Kashering a Pot After a Roommate's Use of it on Shabbat

by Rav Daniel Mann

Question:  I have a roommate who understood he was joining a Shabbat observant apartment. Recently, when I was away, he used our joint pot to cook on Shabbat. Do I have to kasher it?


Answer:  This answer does not deal with the complex issue of sharing utensils with someone who is not consistent regarding basic halachic requirements.

The answer to this question contains a few surprises. You seem aware of the prohibition to eat food cooked in a forbidden manner on Shabbat. We accept the opinion that the prohibition is only due to a rabbinic injunction to penalize one who violated Shabbat (Ketubot 34a). Your excellent question is whether the prohibition extends to utensils.

Some connect this to the question of whether pots in which a non-Jew cooked kosher food (bishul akum) need to be kashered (see Shut Ktav Sofer, Orach Chayim 50). The Shulchan Aruch (Yoreh Deah 113:16) cites two opinions on that matter and slightly prefers the stringent opinion. However, there is more room for leniency regarding food that is cooked on Shabbat. Bishul akum is under the category of forbidden food, which usually requires kashering utensils. In contrast, the prohibition on the food cooked on Shabbat seems to be more generally to prevent benefit from a perpetrated prohibition (Nefesh Harav, p. 174, in the name of Rav Soloveitchik and his father). Two indications of this are the fact that the prohibition is not equal to all people (Ktav Sofer, ibid.) and the fact that the same prohibition applies to non-foods worked on during Shabbat. Since there is no real benefit from trace quantities that seep out of a utensil, it makes sense that the utensils do not become forbidden. After 24 hours have passed since the cooking, there is further reason for leniency because any taste that comes out is assumed to be spoiled to the point that it does not forbid the food cooked in the pot (Pri Megadim, Eshel Avraham 253:39). Despite all of the above, the Magen Avraham (318:1) and the Mishna Berura (318:4) seem to require such pots to be kashered (see explanation in Minchat Shlomo I, 5).

The above, though, is likely irrelevant to you. After all, we accept Rabbi Yehuda’s opinion that even if food was cooked intentionally on Shabbat, it is prohibited after Shabbat only for the person who violated Shabbat (Shulchan Aruch, Orach Chayim 318:1). There is a question whether the food is forbidden also for the person on whose behalf the food was cooked (see ambiguous language in Magen Avraham 318:2). However, the consensus is to permit it (Mishna Berura 318:5). (If the Shabbat violator intended to profit by giving it to another person, e.g., a restaurant owner who cooked on Shabbat so he could sell the food after Shabbat, the matter is more severe (Ktav Sofer, ibid.).) In any case, while your roommate knew you would be using the pot later, presumably he cooked the food for his own use. Therefore, you should have no problem using the pot as is.

However, there is a twist. While you may use the pot, perhaps your roommate may not. If he mustn’t use the pot, then you may violate lifnei iver (putting a stumbling block before those who do not know better than to violate the Torah). On the other hand, we saw that there is much room for leniency in the matter even for your roommate, and the worst-case scenario is not that severe (as the food cooked in the pot will be permitted after-the fact). Therefore, the rules of lifnei iver are highly unlikely to apply (the rationale is beyond our scope).

In the final analysis, you are not required to kasher, and this is all the more so if doing so will send the wrong message to a roommate, who you want to love a Torah lifestyle, not resent it. On the other hand, kashering can also send an important message: you are disturbed by the chillul Shabbat that occurred in your apartment (by someone who pledged not to do so), and it affects your quality of life. Kashering, while being a big stringency here, is not a charade. It is your apartment and your relationship, and you can/must make the call.

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