Included among the thirty-nine melachot are several related to food preparation. In addition to the prohibition against cooking in any form, on Shabbat we are also prohibited from squeezing fruit, selecting, kneading, grinding and mashing. Electrical appliances may not be turned on or off on Shabbat.

Our Shabbat menus reflect our adherence to these various laws. Many traditional Shabbat foods have their origins in the Shabbat laws, including cholent, a warm dish which has been cooked prior to Shabbat, and gefilte fish, which has had all bones removed during its preparation.

Even though cooking boiling, roasting, frying and baking are prohibited on Shabbat, and we may not kindle or extinguish a flame, whether for cooking or any other purpose, there are permissible ways to serve warm food on Shabbat. In fact, it is a mitzvah to eat warm food during the Shabbat lunch. This can be accomplished by keeping food hot on a special covering placed over the stove, as explained below. A gas or electric oven regulated by a thermostat should not be used on Shabbat, since opening and closing the oven door may affect the flame or electricity.

The "Shabbat Stove" - Setting up the Blech

It is permissible to keep food warm on a gas flame or electric burner which has been turned on before Shabbat, as long as the source of heat is covered. This is usually done by covering the stovetop with a thin sheet of aluminum referred to as a blech (Yiddish for "tin"). It is preferable for the blech also to cover the control knobs for those burners which it covers, to prevent one from adjusting the flame on Shabbat.

A blech usually covers two to four burners, of which one or two are left on. If, for example, one wishes to place two pots of food on the blech, it is wise to leave only one burner on. The entire blech will become hot, but the area directly over the burner will be hottest.

When setting up the blech, it is best to use a low flame (or flames) so as not to burn the food. Food can be kept hot effectively even with a low flame.

From a health standpoint, be sure that food kept on the blech for more than an hour remains hot, not lukewarm, to prevent spoilage.

Food placed on the blech for Shabbat must be at least one-third or preferably one-half cooked. All salt, spices and liquid must be added before Shabbat begins.

Keeping Food Warm on the Blech: On Shabbat it is permissible to rearrange those pots which sit directly on the blech, under the following conditions:

  • the food is completely cooked;
  • the part of the blech on which the pot sits is hot to the touch;
  • the food has not cooled down to room temperature.

Warming Cold Food: On Shabbat, one may not place cold wet food, even when fully cooked, into a pot on the blech. However, one may place cold food (such as chicken or kugel) near the fire but not on the blech to take the chill off, as long as it could never become hot (over 113° F) in that spot.

Removing Food from the Blech: One may not serve food directly from a pot on the blech. The pot must first be removed from the blech.

Replacing Pots on the Blech: After removing a pot or kettle from the blech to serve from it, one may replace it on the blech only if all of the following conditions are met:

  • When the pot was removed, the intention was to put it back;
  • The food is fully cooked;
  • The food has not completely cooled off and is still slightly warm;
  • The food has not been transferred to another pot;
  • One holds the pot handle until replacing the pot on the blech. It is preferable not to put the pot down. If necessary, the pot may be placed on a table or any dry place except the floor, as long as one continues to hold the pot.

The Use of a Crock-Pot: The laws concerning the use of a crock-pot resemble those concerning the blech. The cholent stew, whether it is cooked first in a regular pot and then transferred to a crock-pot, or cooked only in the crockpot, should be at least half cooked before Shabbat begins, and the temperature knob should be covered with aluminum foil.

The crockpot must have a removable bowl, which should be taken out before serving, just as a pot is removed from the blech.

In order to return the bowl to the crock-pot on Shabbat, foil or some other material must be placed between the removable serving bowl and the heating element before Shabbat (to serve as a blech). The same rules apply as explained above in Replacing Pots on the Blech, .

Adding to Hot Foods and Liquids

When a hot food or liquid is removed from the blech, nothing may be added to it in the pot until it is transferred to another cup or bowl. In most cases it must be put into a third vessel, such as when adding salt, tea, croutons, etc. to soup or liquid. In addition, if the food from the blech is solid, such as chicken or thick cholent, it should also be allowed to cool down before adding anything to it in a third vessel.

Preparing Hot Beverages: If one wishes to prepare tea, coffee, or other hot drinks, one should set up, before Shabbat, either a kettle of boiled water on the blech or a Rabbinic-approved electric urn .

One may not pour the hot water from the kettle directly onto an uncooked solid or liquid, since this would be considered cooking. Coffee, tea, and cocoa fall into this category. Therefore, to make tea or coffee on Shabbat, use the following method:

  • pour the hot water from the kettle into a clean, dry cup;
  • pour the water from this cup into another cup; and
  • then add teabag, tea essence, coffee, sugar or milk. If using a teabag, do not squeeze it.
  • If using a teabag, do not remove the bag from the drink.

Some authorities recommend that instead of using teabags, a special concentrated "tea essence" be prepared before Shabbat. One cup of tea essence is prepared by allowing six teabags to steep in a cup of boiling water. Use one tablespoon of this concentrate to make a cup of tea.

Other Laws Pertaining to Food Preparation

On Shabbat we are not permitted to squeeze fruit, select, knead, grind, mash, grate, chop, shred, or cut very finely. This applies in many different ways, and one should be aware of these prohibitions whenever preparing food on Shabbat. The following are just a few practical examples:

  • Salads must be made immediately before mealtime, and the pieces should not be cut too small.
  • When mashing foods such as banana or avocado, one should vary the usual weekday method, and do it right before eating. For example, mash with the handle of a utensil instead of a spoon or fork. Vegetables or fruits that have been cooked can be mashed in the usual way.
  • Fruits such as lemons, oranges and grapefruits may not be squeezed for their juice. They may, however, be squeezed directly onto solid foods such as vegetables, salad, or cake, to enhance their flavor.

Borer: On Shabbat it is forbidden to separate or sort out two or more types of items which are mixed together. This melachah is called borer, which means "selection." Selection may be done under the following conditions:

Select that which you wish to use from that which you do not wish to use. For example, if a bowl contains both desirable and undesirable fruit, select the desired ones and leave the rest. Do not pick out the pieces of fruit you don't want. An easy phrase reminds us of the correct way: choose "good" from "bad," not "bad" from "good."

  • The selection should take place only by hand, not by instrument.
  • That which is being selected should be for immediate use.
  • When preparing eggs, fruits or vegetables which have inedible shells or peels, these may be removed on Shabbat immediately before the meal, but not with an instrument especially made for that purpose, such as a peeler. A knife, however, may be used. Some authorities permit the use of a peeler if the peel is edible, as is the case of apples and carrots.

Preparing Food for Children: On Shabbat, there are special ways to prepare formula, warm bottles, mix cereals or mash food for babies or children. Consult one or more of the guides to Shabbat observance available in English or an Orthodox Rabbi.

NOTE: The above melachot on food preparation also affect other activities in addition to those directly involving food. Examples are wiping spills with a sponge, playing with modeling clay, mopping, or sorting broken or unwanted articles such as dishes, chairs or clothing.