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The Dos and Dont's of Re-Heating on Shabbat

Important Standards of Shabbat Food Preparation for the Lincoln Square Synagogue Community

Prohibitions regarding cooking or heating food on Shabbat are based on the Torah prohibitions of not cooking and not using fire on Shabbat and the rabbinic extensions of these laws. Observing them is a personal decision for each individual and family to contemplate on their own. As a community we do not judge anyone for how or whether they implement these laws in their homes. People have a right to grow religiously and move towards observance at a pace appropriate for them. However, it is important for people to know what the community's halachik standards are.

When you invite people to your home, which I would hope becomes a regular activity, you take upon yourself a responsibility to feed those guests food that they are halachically allowed to eat. That means keeping to community standards. In addition to making sure the food you serve is itself kosher according to community standards of kashruth, there are shabbat community standards which you need to observe regarding that food. Food that is cooked on Shabbat, or even heated incorrectly on Shabbat, is prohibited to be eaten. I am confident that these community standards for Shabbat re-heating will help unify our community because they will allow everyone to feel comfortable hosting and being hosted on Shabbat, in any home in Houston. So here goes …

Do not put any uncooked food or beverage on a hot burner, in a heated oven, in a crock pot that is on or in a heated urn on Shabbat itself. Moreover, there are many rules that apply even to fully cooked foods:

Do not heat any liquids on Shabbat: Water or even fully cooked soup or stew - anything that can be poured out - needs to be put on the heat (in an urn, crock-pot, or on the stove) and left there, BEFORE Shabbat.

Do not reheat even solid food that has cooled down (from the refrigerator, for example) either by putting it right on the stove or in the oven. This will render it prohibited to be eaten on Shabbat (for you and your guests). You can reheat cold, solid, pre-cooked food by adhering to any one of the following procedures:

  • Put it on a warming tray ("plata" in Hebrew) which cannot be adjusted (tape the knob if there is one) and is not designed to cook (just to warm).
  • Put it on a "k'deira blech" or a "non-blech" which is a pan of water covered by another pan (not just a plain sheet of metal which is called a "blech”).
  • Put it in a warming drawer or cupboard, which is designed just to warm, not to cook.

"So, what does the blech (metal sheet over the stove) that I grew up with allow me to do?" A simple blech only allows you to return hot food (solid or liquid) which you removed from the stove (and had in mind to return to the stove) back to the stove - while the food remains hot. A blech does not allow you to reheat food once it has cooled down. Without a blech, once you remove food from a stove (even a glass covered stove) you cannot even return it to the stove. A "k'deira blech" — meaning a pan of water covered by another blech (the equivalent of a double boiler) allows you to return cold solid pre-cooked food to the stove.

Do ask the rabbi if you have any questions about these procedures for re-heating. Food on the k'deira/non-blech can be covered with a towel, and it will reheat evenly. REMEMBER: Only solid food which has already been cooked can be reheated. Liquids or uncooked food cannot.

Do eat hot food on Shabbat, if you can. It is a misguided Kara'ite custom to eat only cold food (unless that is what you like). So how is it possible with all of the Do Nots listed above?

Do keep food in a crock pot or on the stove or in the oven overnight, but…

  • Do: Make sure that any food you serve is at least one-half cooked before Shabbat starts (18 minutes after candle lighting). For example, if you are making cholent, make sure you put it in with enough hours to make it minimally edible (hard, chewy, but edible) before Shabbat. If cholent takes five hours to be ready to be served (even if normally it is served after 12 hours…), the rabbis estimated one half of that would allow it to be minimally edible, meaning that you have to give it 2 ½ hours to cook before Shabbat starts.
  • Do Not: Stir food in the crock pot or on a heated stove once Shabbat comes in, at the very least until it is fully cooked. It is preferable to remove the ceramic insert of the crock pot before transferring the contents to a serving dish. (Please note: Adding water to the cholent is a complicated matter and should not be done without consulting a rabbi)
  • Do: Feel free to offer your guests tea or coffee; however, since brewing tea or coffee may be considered cooking, please follow the following special Shabbat procedures (these can be ignored on Yom Tov):
  • You may use instant coffee or tea or essence that is made before Shabbat by putting several tea bags in a cup of hot water, or you may make tea (or coffee) by the most common technique:
  • "K'li sh'lishi" (tertiary vessel) tea: Make sure that the tea bag only is immersed into a cup of water that has been twice transferred from the urn or kettle. For example, hot water is poured from the urn (primary vessel) into a teapot or carafe (secondary vessel) and from there to each person's cup (tertiary vessel). Once it is in their cup, they can then put in the tea bag without any fear of cooking (the water is still piping hot, just a little cooler than it was in the urn).

Do not be scared or intimidated! These laws are meant to be doable, and if you make a mistake, that is exactly what the rules were designed for: to protect the basic Torah laws of not cooking and not using fire on Shabbat. Please speak to the rabbi if you have any questions, doubts or issues regarding any of these standards. They are meant to enhance your Shabbat, not to diminish it. From our home to your home, with wishes for peace and unity,

Rabbi Shaul Robinson

This guide was created by Rabbi Asher Lopatin. It was reviewed and updated by Rabbi Robinson for the LSS community

Tue, May 21 2024 13 Iyyar 5784