More Crockpot Questions

However, the article didn’t delve into the issue of shehiya. (See Shabbos 36b). In Talmudic times, it was common to leave food on a flame that was lit before Shabbos. Indeed, it is a mitzvah to have warm food on Shabbos. Since one could not add fuel to the fire on Shabbos, the fire would eventually diminish and perhaps go out at some point over Shabbos. There was a very real possibility that someone might mistakenly stoke the coals on Shabbos. However, to decree that no food may be left on a fire would make it difficult to have hot food on Shabbos. Chazal therefore gave two options to permit one to leave food on a fire over Shabbos. One way is to remove the coals from the oven. The oven still will stay warm for a while. The second is to throw some dirt or ashes on the flames to smother them somewhat. This diminishes the heat of the oven. This actively demonstrates that one does not want a hot fire. Therefore, this will serve as a concrete reminder to not stoke the coals on Shabbos.

The problem is how to apply those options to crockpots. The first option is not at all possible. There are no coals to remove! The second option is also not applicable – throwing some dirt in the crockpot will not accomplish anything. On a stovetop, it has become standard practice to use a blech, a sheet of heavy metal. This is akin to the second option. The blech reduces the amount of heat that reaches the pot from the fire. Some heat is lost due to the use of the blech. As a bonus, the blech usually covers the stovetop knobs as well. This cover will serve as a reminder as well not to adjust the flame on Shabbos. However, many poskim were hesitant to permit one to simply cover the knobs of the stovetop and not use a blech. That is a new third option not specifically permitted by Chazal.

How can one fashion a blech for a crockpot? Some poskim have suggested lining the interior of the crockpot with aluminum foil. However, others contend that the foil will not diminish the heat reaching the insert and accomplishes nothing. Some have therefore suggested using heavy-duty aluminum foil or multiple layers of regular foil to line the interior of the crockpot. Poskim have suggested covering the knob as well.

Rav Reuven Feinstein, shlita, ruled that regarding a crockpot, one can be lenient and simply cover the knob without any lining (as related to this author by Rav Yehuda Leib Gold). Rav Moshe Heineman, shlita, ruled similarly and said that was the psak of Rav Aharon Kotler, zt”l.

Another issue must be addressed. When does shehiya apply? The Shulchan Aruch (OC 253:1) states that it applies to any food left on a fire that is still “improving.” Since the food is still improving, Chazal feared one may stoke the coals on Shabbos. However, the Shulchan Aruch then cites a second opinion with the prefix, “Some say.” This second opinion holds that food that was already half-cooked may be left on a fire without any blech. The logic is that since the food is already partly cooked, one will not come to stoke the coals. Presumably, there is often enough heat left to finish the cooking process without stoking the coals. The Rema notes that the custom is to follow this second lenient opinion. The Kaf HaChaim notes that Sefardim were likewise lenient and followed this second opinion as well. More recently, the Chazon Ish sanctioned following this lenient opinion. Therefore, if the food in the crockpot is at least half-cooked, no blech is required.

The Mishna Berura, however, advises but does not rule that one should follow the first opinion as well. Therefore, he suggests using a blech even for fully cooked food.

Therefore, if the food in the crockpot is at least half-cooked by the time Shabbos starts, according to the letter of the law, no blech is required. Those who follow the Chazon Ish do not need to be machmir. Those who follow the advice of the Mishna Berura should attempt to be machmir and use a blech even in this situation. What constitutes a blech? According to some, regular foil is adequate. Some suggest heavy-duty aluminum foil. In addition, one should cover the knob as well. Some poskim suggest that simply covering the knob of the crockpot is sufficient.