5786/2026
The Rabbinic Concerns
My older son Binyamin is a sous-vide enthusiast and asked for guidance on how to use this wonderful device to prepare a precisely cooked Shabbat afternoon main course. Since the sous-vide is set up before Shabbat, no Torah-level violations are involved. However, concern for violating the three primary rabbinic prohibitions regarding cooking and warming food and Shabbat - Shehiyah, Hatmanah, and Hachazarah – is very much a concern. However, each can be successfully met as we shall outline.
Shehiyah
Chazal prohibit leaving uncooked food on the fire to cook on Shabbat, lest one come to stir the coals. Adjusting settings is the modern-day equivalent of coal stirring. However, Chazal permit Shehiya in certain circumstances under which they believe stirring coals is not a relevant concern.
One way to permit Shehiya is to place a Blech on the fire. While this is not possible with a sous-vide, some (including Rav Aharon Kotler and Rav Yosef Dov Soloveitchik) suffice with covering the dials to avoid concern for adjustment. While one should satisfy this view and cover the dials, this step is insufficient according to many Poskim, including Rav Moshe Feinstein (Teshuvot Igrot Moshe Orach Chaim 1:93).
Another exception is when the food is cooked, as one is not worried about stirring coals at that point. However, the Tannaim argue about the definition of cooked. Chananiah suffices with the food reaching Ma’achal ben Derosai (marginally edibility; half-cooked), whereas the Chachamim require it to be fully cooked. The Ashkenazic tradition is to follow Chananiah, but the Sephardic tradition goes with the Chachamim. Surprisingly, though, Yalkut Yosef (Orach Chaim 253:1) writes that Sepharadim customarily follow Chanania. He believes that the Shulchan Aruch in Orach Chaim 254:4 changes his mind and codifies Chananiah. He concedes, though, that it is best also to have the food on a Blech to satisfy the stricter view. Even the Bi’ur Halacha (253:1 d”h VeNahagu) writes that it is preferable to follow the Chachamim.
Another approach is to place raw meat (Kidra Chaita) in the sous-vide immediately before Shabbat. In such a case, one will not stir since it takes so long to cook that one will not try to hasten its conclusion. While many, including Rav Yosef Eliyahu Henkin and Rav Yosef Dov Soloveitchik, say that Kidra Chaita option does not apply in efficient modern-day gas ovens, it is relevant to the sous-vide set to cook food that will not be ready until the next day.
Thus, to address Shehiyah concerns, cover the knobs, and either cook the food at least halfway before Shabbat or place raw meat right before Shabbat’s start. There is even more room for leniency with sous-vide machines that are controlled by one’s phone. Securely storing one’s phone for Shabbat where it is very difficult to access, arguably removes concern for adjusting the device, similar to lining an oven opening with clay (Tach B’Tit, Shabbat 18b).
Hatmana
Chazal forbade insulating food even on Erev Shabbat if the material heats the food. In the sous-vide, the food is placed in a hot water bath before Shabbat, which seems to create a Hatmana issue. OU Kosher presents two opinions about this question:
Shulchan Aruch (OC 257:8) rules that it is prohibited to insulate food and place it on a fire before Shabbos. Even if everything is performed before Shabbos, this is included in the prohibition of hatmana, which is restricted because it might lead to adjusting the fire on Shabbos. Accordingly, it would seem that one may not use a sous vide machine over Shabbos, since the food is wrapped inside a plastic pouch and submerged into hot water that is still being heated on Shabbos. However, Sefer Piskei Teshuvos (258:3:25) cites many Poskim (e.g., Sefer Az Nidberu, Rav Shlomo Zalman Auerbach, Teshuvos V’hanhagos) who permit this type of activity if the intent of the pouch is not to insulate, but rather to protect the taste and keep the foods separate. According to this view, one may use a sous vide machine over Shabbos. Others follow a stricter view and do not use a sous vide machine for Shabbos.
The strict view argues that one is insulating the food in the hot water, but the lenient approach contends that the plastic pouch surrounds the food, not the hot water.
While OU Kosher does not resolve this matter, there are three points of support for the lenient approach. First, while the Mishna Berurah (258:2) believes that Hatmana applies even when food is insulated by food or hot water, Yalkut Yosef (Orach Chaim 257:6) rules that it does not. Even those who do not follow the Yalkut Yosef may use his opinion as a S’nif L’Hakeil. Second, some Rishonim (cited in the Rama to Orach Chaim 257:1) say that Hatmana applies only to food prepared for Friday night. According to this view, we are not concerned that he will stir the coals for food that is only to be eaten during the Shabbat afternoon meal. While we do not follow this view, it may also serve as a valid S’nif L’Hakeil.
Finally, Binyamin observes that sous-vide cooking involves preparing food at a precise temperature, which users do not adjust based on unpredictable results, as happens with conventional cooking. Thus, stirring coals is not a relevant concern for sous-vide. Although the Halacha applies even when its reason does not, Binyamin’s point inclines us to support the lenient view. Considering that Hatmana is a rabbinic, not Torah-level concern, one may follow the lenient view.
Removing Food from the Sous Vide on Shabbat Afternoon
TABC alumnus and parent Avi Shteingart points out that when one removes the food from a running sous-vide machine, its temperature is lowered and appears on a digital read-out (for machines so equipped). To avoid this concern, Avi programs his sous-vide to turn off before he removes its cooked contents for the Shabbat afternoon meal.
Hachazarah
Returning fully cooked food to a sous-vide machine to warm should not be done. If the machine is on, placing the food in the machine will raise the water temperature and cause a digital read-out. Setting a timer to turn on the machine automatically after one places the food to warm is debated, with the Chazon Ish forbidding. One should be strict on this issue, especially since (as Binyamin reports) people do not typically warm food with a sous-vide.
Conclusion
Setting a sous-vide to prepare a beautiful hot meal for Shabbat afternoon is a wonderful way to fulfill the Mitzvah of Oneg Shabbat. One need only follow the guidelines we set forth, which are practical and doable. However, since the matter is still a matter of debate, one should adopt the strict view for community events such as a Beit Knesset.