It is very common among Shabbat-observant Jews to use a “crock pot,” or slow cooker, for preparing food – such as Hamin – for Shabbat morning. The crock pot consists of a pot that is placed inside a mechanism that has a heating element on the bottom and surrounds the pot of food. The food inside the pot cooks slowly, at a speed that can be determined with a dial. Because the food cooks at a slow pace, this device is very well-suited for preparing meals for Shabbat, when cooking is prohibited. Many people place the raw Hamin in the crock pot and turn it on before Shabbat, and the food cooks throughout Friday night and is ready to be eaten fresh at Shabbat lunch.
One might, at first glance, question the Halachic propriety of using crock pots for Shabbat in light of the prohibition of “Hatmana,” or “insulating.” The Sages enacted a prohibition against insulating a pot of food before Shabbat to keep it warm for the Shabbat meal. Even though the insulation is prepared before Shabbat, and even if the insulation only maintains the food’s heat, and does not generate additional heat, insulating food for Shabbat is forbidden. In Talmudic times, hot food was commonly insulated in smoldering coals, and the Sages feared that in a person’s anxious desire to keep the food warm, he may stoke the coals on Shabbat, which would constitute a Torah violation. They thus forbade insulating food before Shabbat as a safeguard against stoking the coals.
Would it be permissible, then, to place food in a crock pot before Shabbat to cook on Friday night? After all, the crock pot operates through “insulation,” as the pot of food is surrounded by the outer mechanism which generates heat through an electric current and cooks the food.
Hacham Ovadia Yosef addressed this question and ruled that one may use a crock pot for cooking food on Shabbat, due to a combination of a number of different factors.
First, some Halachic authorities held that the “Hatmana” prohibition applies only to food that one wishes to eat on Friday night. In this case, a person is anxious to keep the food warm for the Friday night meal, and he might therefore stoke the coals. But if one insulates food that he intends to eat only on Shabbat morning, he does not even think about the food at all. In the case of a crock pot, after one turns on the mechanism before Shabbat, it is not on his mind at all until he removes the food on Shabbat morning. Although other authorities dispute this ruling, we may combine the lenient position with other factors as a basis for allowing the use of crock pots.
Secondly, according to some authorities, one violates the “Hatmana” prohibition only if he covers the entire pot. In the case of the crock pot, the outer mechanism does not cover the top of the pot. Of course, the pot is covered with a lid, but the lid is considered part of the actual pot of food, and not part of the insulation. Hence, the pot is not entirely covered. It should be noted that it would thus be improper to cover the top of the crock pot with towels or rags to maintain the heat, as this would result in the insulation of the entire pot.
Thirdly, some authorities held that one violates “Hatmana” only if the pot of food comes in direct contact with the insulating material. In a crock pot, there is a small space of air in between the pot of food and the outer mechanism, such that it would not violate the “Hatmana” prohibition according to this view.
Yet a fourth consideration is a view among the Poskim that limits the “Hatmana” prohibition to situations where there is indeed cause for concern that one may mistakenly increase the heat in his anxiety to maintain the food’s temperature. As mentioned, in Talmudic times, food was generally insulated with coals, which gradually lose their heat over the course of time. This gave rise to the concern that one may stoke the coals to maintain or increase their temperature. The mechanism of a crock pot, by contrast, operates through an electric current, and thus its heat remains constant and does not diminish with time. There is thus no reason to fear that a person may tinker with the mechanism in an effort to maintain or increase the food’s temperature.
Taking into account these considerations, Hacham Ovadia concludes that it is permissible to place raw food in a crock pot before Shabbat and have it cook in preparation for the Shabbat morning meal. He adds, however, that one must either cover or remove the knob that controls the speed of cooking, in order to ensure that one may not mistakenly change the pot’s temperature during Shabbat. For example, one can take a small piece of aluminum foil and tape it over the dial, as a reminder not to turn it on Shabbat.
Rav Yosef Shalom Elyashiv (contemporary) likewise ruled leniently on this issue. A crock pot was brought to him in his home and he was shown how it operates. After viewing the demonstration, he ruled that it is entirely permissible to use it for Shabbat in the manner described.
Summary: It is permissible to place raw food in a crock pot before Shabbat so that it will cook through the night in preparation for the Shabbat morning meal. One must, however, either cover or remove the dial that controls the cooking speed, and one must not cover the top of the pot with towels or other material.
