Covering the Stove (Blech)

The Aish Rabbi Replies

Ah, yes – the Shabbos blech! After the candles, challah, and Kiddush cup, it must be the most salient aspect of the Sabbath-observant home – even rating higher than the kneidelach (matzah balls).

I’ll begin by writing that there is an ancient Jewish practice to serve hot food on Shabbat, both by night and day (Rema O.C. 257:8). This is in part to increase our enjoyment of Shabbat, but also to repudiate the practices of the Karaites, who rejected the interpretations of the Sages. They took literally the verse “You shall not burn a fire in all your dwellings on the Sabbath day” (Exodus 35:3), rejecting our tradition that a fire lit before Shabbat may continue to burn. Thus, partaking of a delicious chollent stew on Shabbat day, apart from the culinary enjoyment, is a form of honoring the Sages!

As an aside, “blech” is Yiddish for “tin” – which is what I suppose was traditionally used. The ‘ch’ is pronounced as the German KH sound (ich, Bach, etc.).

As I wrote above, there is no problem with leaving a fire burning from before Shabbat, and likewise, so long as the pots were placed on the fire before Shabbat, there is no prohibition with allowing them to continue cooking. Although cooking is a forbidden Shabbat labor, so long as you place the pot on the fire before Shabbat, you are not cooking on Shabbat. Your act was completed beforehand.

If so, why the need for a blech? The Sages were concerned that if food was not sufficiently cooked before Shabbat – or even if it was fully cooked but will improve with additional cooking, a person may come to increase the flame to hasten its cooking (Talmud Shabbat 18b; see also Mishnah Berurah 253:24). They therefore required that some distinction be made to remind us not to adjust the fire. In the olden days, this would entail removing or covering the coals of the oven. Today, with our gas or electric ranges with knobs to adjust the heat, this “distinction” is achieved by covering both the burners and the knobs (Igros Moshe O.C. 93).

According to many opinions, once the food is cooked enough to be edible (either 1/2 or 1/3 of the way), there is no concern a person will increase the fire. One may rely on that opinion in times of need (see Shulchan Aruch and Rema 253:1 with Bi’ur Halacha s.v. “v’nahagu”).

A second reason for the blech is in case a person wants to remove a pot from the fire, take some food out, and return the pot to the fire. (One should not remove food from a pot while it is still on the fire. According to some, the inadvertent movement of the food caused while taking some of it out is a form of “stirring” – and it is forbidden to stir even fully-cooked food while directly on the flame (Mishnah Berurah 318:113).)

Now, needless to say, one would never be able to return a not-fully-cooked pot to the fire on Shabbat – since that is the labor of “cooking”. However, even if a pot is fully cooked, the Sages forbade returning a pot to the flame because it appears like cooking (Mishnah Berurah 253:37). This concern is in part addressed with a blech, since the pot is no longer being placed directly on a flame.

Once we’re on the subject of returning a pot to the fire, I will list all 5 conditions required for doing so: (a) the food is fully-cooked, (b) the flame is covered with a blech, (c) the food is still warm, (d) the pot has not left your hands (even if it’s resting on the counter), and (e) you intended to return the pot when you removed it. (There is room to be lenient if you didn’t fulfill the final two conditions; beyond the scope of our current topic.)

Finally, if you want a very good overview of these laws, I suggest signing up for the Laws of Shabbat course offered by The Aish Academy.