Our fast paced lifestyles have opened a market for easy to prepare and pre-cooked types of foods. Ready to eat, heat-and-serve or just add boiling water. Packaging labels proclaim that you can have that old fashioned home cooked flavor in only a fraction of the time. For the kosher consumer there are a variety of concerns that present themselves when using these quick to prepare concoctions. As can be expected, the less you have to do at home to prepare, the more that has been done at the factory to make the food edible. Therefore, one must be sure that the product has reliable kosher certification.
One must also be cautious as well when using these processed foods on Shabbos. As a rule, when dealing with raw foods, the Shabbos observant consumer will prepare all foods in advance of Shabbos. This is done to prevent transgression of the Torah’s prohibition of cooking on the Shabbos day. Dealing with foods that are pre-cooked may provide some leniencies, however, one must be educated in how and where these leniencies may apply. This article intends to give an overview of the basic laws relevant to the prohibitions involved in warming and re-heating foods on Shabbos, followed by practical applications regarding the use of these instant preparations on Shabbos.
The Torah prohibits doing any work on the Shabbos Day. Work, in this context, is defined as the thirty-nine constructive activities done to build the Mishkan (the Tabernacle), and their sub-categories. Among those actions done to build the Mishkan was cooking. Therefore, the act of cooking may not be done on Shabbos. The question is, aside from actually placing cold raw food on a flame to boil, how far does this prohibition extend?
What Do We Call Cooking?
The Torah’s prohibition of cooking is not restricted to placing raw food on a flame and bringing it to a boil. Heating foods to a temperature that is defined in the Talmud’s terms as yad soledes bo (approximately 120° F), is enough to constitute cooking. Even where one intends on warming to a degree that is less than yad soledes, it is prohibited to place food to be warmed on or into a heat source that is hotter than yad soledes because one may forget and leave it until it is actually hot.
Kli Rishon & Kli Sheni
The Talmud refers to the pot used for cooking on a heat source as a kli rishon. As a rule we say the kli rishon will cook that which is placed into it as long as it is hot (yad soledes bo). This is so even after the pot has been removed from the flame. We also say that direct pouring from this pot will cause cooking to at least the outer layer of the food that it comes in contact with 1. Cooking of the outer layer alone is enough to prohibit this action on Shabbos. Generally we assume that the kli sheni, the secondary vessel, meaning the container into which hot liquid was poured, will not have the ability to cook 2. Nevertheless uncooked foods that were not steeped in hot water before Shabbos should not be steeped in a secondary container on Shabbos 3. We must bear in mind that there are uncooked foods that are readily cooked in hot water even in a kli sheni. These are referred to as kalei habishul. If one were to add such ingredients to a secondary container while it is hot this would be considered outright cooking. A common example of this is tea leaves.
Instant Foods on Shabbos
Aside from the obvious Torah prohibition of cooking on Shabbos we must also be concerned with Rabbinic prohibitions when reheating food on Shabbos. Among the Rabbinic prohibitions are those of hatmana and chazara.
Hatmana is where the food is wrapped or enveloped by insulation to preserve or add heat. Both of these actions are prohibited on Shabbos. Where heat is increased by the wrapping of the food container, one may not do so even before Shabbos.
Example: one may not completely submerge a food packet or baby bottle in hot water to warm them on Shabbos. To warm a baby bottle in water, one must be sure that the water level remains below the height of the inserted container.
Chazara means returning a cooked food to the hot cooking surface on Shabbos. This is prohibited because it may look like you are beginning to cook. This prohibits placing any foods to be rewarmed directly into a hot oven, onto a heated cooking surface, or into a pot sitting on a hot cooking surface. This is prohibited even where the heat source is covered and the food has been completely cooked4.
Reheating Cooked Foods
Let us now look at the prohibition of cooking on Shabbos as it may relate to our question. We know that one may not prepare raw or uncooked food by heating it on Shabbos. The Shulchan Aruch5 teaches that there is no prohibition for reheating foods that were completely cooked before Shabbos6. This refers to placing foods into the pot used for cooking that is no longer on the heat source. As previously noted, chazara prohibits placing cooked food directly onto a hot cooking surface on Shabbos.
It is important to note that when we say reheating pre-cooked foods is permitted, we are referring to foods that have been made edible through boiling in liquid. One may not mix or heat baked or broiled foods with hot liquids on Shabbos. This rule applies even in a kli sheni7.
This rule is also limited to foods that are now yavesh, dry. Where the food is liquid or has liquid and is no longer warm, one may not reheat it on Shabbos8. Therefore one should not add cold pre cooked liquid 9 to a kli rishon or pour from the kli rishon onto cooled liquids.
With these rules in mind we see that to warm instant or pre-cooked foods on Shabbos we must determine how the foods were manufactured. Are they cooked in liquid, baked, roasted, steamed etc.? We must also see what state they are in now. Are they liquid or solid? How do we intend to warm them on Shabbos? Do we intend to place them into the cooking pot, pour onto them from the cooking pot or place them into a secondary vessel?
Salt – The Shulchan Aruch cites two opinions regarding placing salt in a kli rishon on Shabbos. One states that salt is not easily cooked and must remain on the fire for a long period of time to become cooked 10. According to that opinion one may add salt to the hot pot when not directly on the flame. A second opinion states that salt is readily cooked, and should not even be added to a klei sheni 11 . The Mishna Berurah notes that the first opinion is the accepted opinion, however it is best to be strict when possible. He goes on to note that this refers to rough salt that has not been cooked in its processing. Our granulated salt has been cooked during its refining and is considered a dry food that has been pre-cooked. The Mishna Berurah concludes that such salt may be added to a pot on Shabbos when no longer on the fire without fear of transgression even according to the stricter opinion.
There are gourmet salts that are only evaporated sea salts. These have been produced by solar evaporation of sea water. If these salts were not further processed using boiling water to refine or break down the salts, then according to the second opinion in the Shulchan Aruch one may not add such salt to hot foods on Shabbos. This is prohibited even in a kli sheni as they are kalei habishul.
Instant Coffee & Tea – Many powders or crystals that are made to be added to water are pre-cooked. For example instant coffee is made by cooking the roasted coffee bean grounds as one would make fresh coffee. The coffee solids are removed and the brew is then spray dried or freeze dried to remove the remaining moisture. The resulting powder or crystals are your instant coffee. The same type of process is used to manufacture instant tea. Flavored instant teas add powdered flavors that are cooked and spray dried extracts from natural or artificial sources. As a result they may be used on Shabbos (preferably in a kli sheni). Coffee bags are a blend of instant and ground roast coffees. Due to the ground roast content they should not be used on Shabbos.
Oatmeal – Instant oatmeal is made by steaming fine cut oats. They have not actually been cooked in water to make them edible. Can you imagine trying to unstick oatmeal that was already stuck together? In addition, flavored instant oatmeal may have raw spices, such as cinnamon, added to give flavor. All things considered, hot water should not be added to instant oatmeal on Shabbos.
Baby Cereal – Instant baby foods are pre-cooked with liquid to make a slurry. This mixture is then dehydrated and ground. From a cooking standpoint such a product may be used. However, it must be noted that where a mixture is thick enough so that it is not free-flowing, one must be concerned with lisha, the Torah prohibition against kneading dough on Shabbos. Thicker consistencies are also considered dough-like, therefore the mixture should be made to a loose consistency (blila raka) and the mixing must be done with a shinuy, in a manner that it is not ordinarily done. For example, if one ordinarily adds the powder and then the water, on Shabbos one should add the water and then the powder. Enough liquid should be added to make the mixture a blila raka12. The ingredients should then be mixed in an uncommon way. For example, with one’s finger rather than a spoon or in a criss-cross motion rather than a circular motion, using the handle of a spoon.
Baby Formula – Baby formula powders are pre-cooked in their processing, and may be mixed with hot water on Shabbos.
Milk Powder – Dry milk powders are made by boiling the milk to evaporate the bulk of the water content. They are then spray dried to make them into a powder. As such they can be used with hot water on Shabbos.
Sugar – Granulated sugar (beet & cane) is pre-cooked in its manufacturing process. So called raw sugar is also cooked as part of its extraction process from the sugar cane. These may be used with hot liquids on Shabbos.
Equal – The sugar substitute aspartame found in Equal is heated as a liquid before being crystalized and may be used with hot fluid on Shabbos.
Pasta – Most noodle and pasta products are not cooked during production, rather they are made from dough that is extruded and dried. Heating them in a cooking pot would be prohibited.
Cocoa – Cocoa powder processing does not involve actual boiling of the product. The nibs (as the seeds are called) are roasted, and then ground to form a liquid solution called chocolate liquor. At this stage the product may reach temperatures exceeding 90 centigrade. This cocoa liquor is then heated under pressure to extract the cocoa butter and separate the pulp from the remaining liquor. The remaining pulp which is the base for cocoa powder is later re-fortified with chocolate liquor for flavor and color. Instant cocoa can be made from regular cocoa with added sugar and emulsifiers which help disperse the cocoa powder and bring out its taste. As such the cocoa or instant cocoa has not gone through a complete cooking phase as a liquid or with a liquid. Therefore it should not be used in a kli rishon nor should one pour hot water onto it from a kli rishon on Shabbos.
Instant soups – Powdered soup mixes are often mixtures of dehydrated pre-cooked and non pre-cooked ingredients (e.g. vegetables) and should not be used on Shabbos. Regarding instant liquid soups, we have already noted that reheating cooled liquids is considered cooking on Shabbos. Therefore one should not mix them with boiling water on Shabbos. As mentioned before if the liquid soup is in a packet there would be additional concern if submerged in the hot water because of hatmana.
Our Rabbis give an example of one who uses foresight saying “One who prepares food on Shabbos Eve (prior to sundown) will eat on Shabbos“. Instant foods have found their way into our kosher kitchens. Nevertheless, we must use foresight and be conscious of how we use these foods so that we can enjoy the taste of the true Olam Haboh.
Special thanks to Rabbi Zushe Blech, Mr. Fabien DeClerq of OCG Cacao and Mr. Donald Schoenholt of Gillies Coffee Company for their technical advice.
1. Irui mevashel k’dei klipa.
2. Kli sheini aino mevashel.
3. Rema, Orach Chaim 318:4, Mishne Berura 38.
4. There are circumstances where one may return a hot pot to the heat source. This depends on the food being fully cooked, the heat source being covered and one’s having intention to return it to the heat from the time that it was removed from the heat. The pot should be held from the time it is removed from the heat source until it is returned.
5. Orach Chaim 318:4.
6. Ain bishul achar bishul.
7. Rema, Orach Chaim 318:5, Yeish bishul achar afiya, yeish bishul achar tzli.
8. The Rishonim argue about bishul achar bishul on liquids. The opinion of the Shulchan Aruch is that reheating a liquid is equal to the initial cooking.
9. Note: Some opinions consider dry foods that dissolve when added to hot liquid a davar lach, a liquid. To allow for this opinion, it is better to put such additives only into a kli sheni after the hot liquid has been added. For example, it is best to first place hot water into a cup and then add instant coffee.
10. Melach tzarich bishul k’bisrah d’turah.
11. Kalei habishul.
12. Where there is no standard order one should add the food before the liquid as this is the shinui stated in the Gemara (Mishne Berurah 321:57).
bishul achar bishul – cooking that which has already been cooked.
blila raka – a loose or batter-type mixture.
chazara – returning cooked food to the heat on Shabbos. As a rule, this action is Rabbinically prohibited on Shabbos because it looks like you are putting food up to cook.
davar lach – liquid or wet.
halacha – religious laws governing Jews.
hatmana – wrapping of food containers to maintain or increase heat.
kalei habishul – things that are easily cooked with even a minimal amount of heat in a short amount of time.
kli rishon – primary vessel used on heat source to heat up the food.
kli sheni – secondary vessel into which contents of kli rishon have been placed.
lisha – kneading dough. Kneading dough is a primary act of work done in the construction of the Tabernacle and is prohibited just like cooking.
me’ein Olam Haboh – similar to The World to Come. The peace found in resting on Shabbos day is said to bear similarities to the pleasures of The World to Come.
Mishkan – Tabernacle.
Mishna Berurah – halachic work compiled by Rabbi Yisroel Meir Kagan.
Olam Haboh – the world to come.
Rema – halachic work notes on Shulchan Aruch compiled by Rabbi Moshe Isserles.
Rishonim – early Rabbinic authorities and commentaries.
shinuy – an uncommon way to do an action. Some actions which are prohibited may be done in an uncommon way which will not be confused with the actual prohibition.
Shulchan Aruch – code of Jewish law as compiled by Rabbi Yosef Caro.
Talmud – primary source of Rabbinic law and interpretation of the Bible.
Torah – Bible.
yad soledes bo – too hot to place one’s hand into, measured at approximately 120° F.
yavesh – dry.