5786/2025
Introduction
A crucial rule permitting us to enjoy hot food on Shabbat is the principle of Ein Bishul Achar Bishul (literally, “there is no cooking after cooking”). There are several crucial debates concerning this central idea.
Liquids
The Rishonim debate whether Ein Bishul Achar Bishul applies only to solids or even to liquids. The Biur Halachah (318:4 s.v. Yeish) notes that the Rambam, Rashba, and Ran adopt the lenient position that Ein Bishul Achar Bishul applies even to liquids. However, Rashi, Rabbeinu Yonah, the Rosh, and the Tur are stringent and believe that Ein Bishul Achar Bishul applies only to solids. The Acharonim (see Pri Megadim Eishel Avraham 254:1 and Eglei Tal Ofeh 8:11) explain that the stringent view believes that the effect of the cooking of a liquid is nullified after it has cooled down (Azil Lei Bishulei). By contrast, solids retain the impact of cooking even after the food has cooled. The lenient opinion believes that Ein Bishul Achar Bishul applies even when its reason is irrelevant.
Many Yemenite Jews follow the Rambam and will reheat liquid (such as the famed Yemenite soup) on Shabbat. Sepharadim follow Rav Yosef Karo, who codifies the strict view (Shulchan Aruch Orach Chaim 318:4 and 15). According to Rav Karo, one may not reheat liquids that have fallen below Yad Soldet Bo. The Rama (O.C. 318:15), however, cites the lenient view. The Rama records the Ashkenazic practice to follow the lenient opinion if the liquid “has not completely cooled.” Acharonim debate how to understand the Rama’s phrase, “not completely cooled down.” The Eglei Tal (Ofeh 8) explains that it refers to liquid that is less than Yad Soledet Bo but is still sufficiently hot that people regard it as a hot drink. The Chazon Ish (O.C. 37:13) indicates that the Rama is lenient if the liquid is not entirely cooled.
Acharonim also debate the reasoning behind the compromise. At first glance, the compromise appears difficult since reheating a liquid that fell below Yad Soledet Bo constitutes Bishul according to the strict opinion. On the other hand, the lenient opinion permits reheating a liquid even if it has completely cooled down. The Halacha appears to attach no significance to the liquid not having been completely cooled down.
The Chazon Ish (ibid.) explains that the Rama fundamentally accepts the lenient view as the normative position. However, there is concern that if an item is completely cooled down, it will be difficult to distinguish between the cooled liquid and liquid that has never been heated. The common practice seeks to avoid this potential confusion.
Rav Yosef Dov Soloveitchik (cited by Rav Mordechai Willig, Beit Yitzchak 21:181), on the other hand, suggests that the Rama fundamentally accepts the stringent opinion as the normative position. Rav Soloveitchik explains that the strict view believes that when a liquid cools down, no impact remains from the cooking (Azil Lei Bishulei). Accordingly, as long as the liquid has not completely cooled down, some of the original cooking effect remains, and one is not considered to be cooking.
Defining Liquids and Solids
Acharonim have debated the definition of liquid and solid in this context for centuries. Some Acharonim (the Bach, Vilna Gaon, and Mishna Berura) believe that a food must be free of any liquid to qualify as a solid. Other Acharonim (including the Taz, Pri Megadim, and the Kaf Hachaim) believe that if the majority of an item is solid, it is classified as a solid (the opinions are summarized by Rav Shimon Eider, Halachos of Shabbos, p. 259 footnote 114).
Rav Yosef Adler ZT”L cites Rav Yosef Dov Soloveitchik, who offers the following practical guidelines. If the food is eaten with a fork, it is solid, and if it is eaten with a spoon, it is liquid. Rav Ovadia Yosef (Teshuvot Yechaveh Daat 2:45) also follows the lenient view. On the other hand, Rav Moshe Feinstein (Teshuvot Igrot Moshe 4:74:Bishul:7), Rav Ben Zion Abba Sha’ul (Teshuvot Ohr L'Tzion 2:30:13), and Rav Shalom Messas (Teshuvot Tevu’ot Shemesh Orach Chaim 66) are strict. Rav Mordechai Willig advises following the strict view.
Rav Eider (ibid.) defends the lenient view based on the Chazon Ish’s understanding of the Rama. The concern of confusing cooled-down liquid with another is not relevant if the liquid is mixed in a majority of food.
Practical Application – Tea Refills
An interesting question arises regarding refilling a cup of tea or coffee. Some Poskim (Rav Aharon Kotler and others, cited in Halachos of Shabbos, p. 295, note 423) require wiping the remaining few drops of completely cooled water on the cup’s bottom. Many authorities, though, are lenient. The Chazon Ish (ibid. note 424) rules leniently, arguing that we fundamentally accept that Ein Bishul Achar Bishul applies to liquids. The Ashkenazic custom to follow the strict view if the liquid has entirely cooled down, argues the Chazon Ish, does not apply if one merely reheats a minute amount of water and does not care about reheating the few drops.
Rav Moshe Feinstein (Teshuvot Igrot Moshe O.C. 4:74:Bishul:19) argues that one may be lenient because of multiple doubts (S’feik S’feika). One lenient consideration is that many Rishonim permit reheating liquids. The second lenient consideration is that one is not concerned about reheating such a minuscule amount of water. This is a situation of a פסיק רישיה דלא ניחא ליה (an unintended side effect) and is permitted by some Rishonim (most notably the Aruch). The combination of these two lenient opinions allows for a lenient ruling. This ruling also applies to returning a ladle to a Kli Rishon if it has a few drops of previously cooked liquid that have cooled completely.
However, Rav Mordechai Willig (Cooking and Warming Food on Shabbat, p.26) follows the strict view, keeping with Rav Soloveitchik’s understanding of the Rama’s compromise.
We will complete our discussion in the next section.