Ein Bishul Achar Bishul: Re-Cooking on Shabbat

Two gemarot in Massekhet Shabbat (39a and 145b) assert that once an item has been cooked prior to Shabbat, it can be re-cooked on Shabbat without violating the prohibition of bishul, based on the principle of “ein bishul achar bishul.” In this shiur, we will explore this exception and the manner in which this rule reflects the nature of the bishul prohibition.

The simplest explanation for the rule of ein bishul achar bishul is that bishul is only violated if cooking enhances or improves an item. Inasmuch as Shabbat violation must create change, bishul only occurs if the food is altered. Pre-cooked food is not altered by the second cooking process, and therefore no bishul violation entails.

This logic may be challenged by an interesting position of the Rashba regarding the degree of initial cooking necessary to allow subsequent cooking on Shabbat. Tosafot (Shabbat 39a) claim that the food must be pre-cooked entirely in order to allow a second cooking. By contrast, the Rashba and the Rosh claim that as long as the food is initially 33% cooked (“ke-ma'achal ben derusai”) it can be re-cooked without any issur. If the initial cooking has only partially processed the food, the second cooking does, in fact, render change and improvement. Since it transforms partially cooked food, the second cooking should be prohibited according to the aforementioned logic explaining the leniency of ein bishul achar bishul.

Evidently, these Rishonim adopt a different logic to explain ein bishul achar bishul. Perhaps the second cooking process is considered halakhically meaningless because it is merely repetitive. As the re-cooking isn’t considered a formal act of bishul, no violation has been perpetrated. This logic presumes that bishul is only violated if a process of cooking has been executed. Cooking already-cooked food is repetitive and insignificant, and no violation occurs. Once the food has undergone an initial cooking process – even partial – the second act is not considered cooking and no violation occurs.

There are thus two different logics to explain the permissibility of a second bishul. Perhaps the second bishul renders no improvement, and it therefore is not a violation. Alternatively, the second act may be a repetitive act, and it thus does not entail a violation. The nafka mina between these two understandings would be a situation in which the food was initially only partially cooked, in which case the second process is repetitive, but improves the item.

A second nafka mina may relate to the difference between recooking solid foods and recooking liquid substances. The Rosh (Shabbat 3:11) claims that Rashi prohibits the re-cooking of liquid-based foods; the allowance of re-cooking only applies to solid foods. By contrast, most Rishonim – as first articulated by the Rashba – disagree with Rashi’s restriction and extend the allowance to re-cook even to liquid-based foods.

Perhaps this novel position of Rashi is based on his definition of why re-cooking is permitted. If the first cooking renders the re-cooking repetitive and meaningless, it is difficult to envision a difference between solid and liquids. In both scenarios, the second cooking is superfluous and no violation should entail. If, however, the reason that re-cooking is permitted is the absence of any tangible improvement, perhaps liquids are different. Heated liquids are significantly more pleasurable that cold liquids, in a manner inapplicable to solids. Thus, re-cooking liquids may render improvement, which entails a violation of bishul. Perhaps Rashi’s view of the principle of ein bishul achar bishul yields an exception to this rule, a case in which re-cooking liquids is prohibited because it entails improvement to the food.

This logic to explain the prohibition of re-cooking liquid foods is especially compelling considering an interesting qualifier imposed by Rabbeinu Yonah. In his comments (cited by Rabbeinu Yerucham), he claims that re-cooking liquids is only forbidden if the re-cooking improves the quality of the liquid. Improvement cannot be measured solely in terms of the benefit of heat; some actual taste improvement must occur. Evidently, then, improvement per se determines the prohibition, even though the second act of cooking is redundant and meaningless.

A more broad consequence of the two different ways of understanding this rule relates to its applicability to non-Shabbat areas of Halakha. Is re-cooking permitted in other situations in which cooking is forbidden? For example, can a meat and dairy mixture be re-cooked? The Rema (Yoreh De'ah 87:6) claims that it is forbidden, whereas the Shach (87:18) claims that it is permitted. Some view the Shach's allowance as based on the principle of ein bishul achar bishul imported from Shabbat. Presumably, he learned from hilkhot Shabbat that a second act of cooking is meaningless, and it is therefore also meaningless when performed on a meat and dairy mixture. If the exemption of Shabbat were based upon the lack of improvement of the second cooking, it might be limited to Shabbat, where creative improvement is crucial for the violation to apply.

The Tzelach (Shabbat 145b) articulates this question about the exportability of the ein bishul achar bishul exemption to non-Shabbat areas of Halacha. The distinction between Shabbat cooking (which requires improvement) and meat and dairy cooking (in which any act of cooking is prohibited), with the resultant distinction regarding the applicability of ein bishul achar bishul, is attributed to Rav Chaim Brisker.