Rules of בישול אחר בישול

Melacha of Bishul

  1. The melacha of bishul on Shabbos is taking something raw or partially cooked and cooking or baking it through a cooking method, thereby upgrading it to a cooked or baked item.

No בישול אחר בישול on Davar Yaveish [Dry Food]

  • However, the issur of bishul does not apply to a dry food that was already fully cooked. Once it was already prepared through cooking, cooking it again does not improve or add to it. Initially cooking a food, not merely heating it, is its main improvement.
  • For example, a raw potato kugel is totally inedible. Baking it is its main improvement – it is now a baked kugel. Thus, one would be chayav for baking it on Shabbos. However, if it was baked before Shabbos, its main improvement was already completed; though it is nice to eat hot kugel, heating it on Shabbos is not its main improvement. We apply the rule of אין בישול אחר בישול to a davar yaveish, and one may heat it on Shabbos. But Chazal only allowed heating food in certain ways – i.e., not “nesinah techilah” or “chazarah,” as will be explained (below, 22).

בישול אחר בישול on Davar Lach [Liquidy Food]

  • יש בישול אחר בישול. Regarding a davar lach, e.g., water, soup, or a dish with broth such as cholent, the Rishonim argue whether one may reheat it on Shabbos if it was cooked before Shabbos and then cooled. Some say יש בישול אחר בישול for a davar lach, and it is assur. The reason is that the main effect cooking has on a liquid is heating it. When it cools, the whole benefit from the initial cooking is gone, so when one reheats it, he is cooking it anew (רא”ש שבת פ”ג סי”א בדעת רש”י, עליות דרבנו יונה ב”ב דף י”ט., סמ”ק יום השביעי עמ’ רפ”ח, טור).
  • אין בישול אחר בישול. Others hold אין בישול אחר בישול is true even of a davar lach that has completely cooled, as the benefit of the initial cooking remains. Even plain water that was once cooked and cooled has an advantage over water that was never cooked (דרשות הר”ן דרוש ח’ ד”ה ההקדמה השלישית, אגלי טל אופה סקי”ט אות י”ב); a soup or cooked dish certainly retains the benefit of cooking even after it has cooled (רמב”ם, רשב”א ור”ן המובאים בב”י סי’ שי”ח).
  • Mechaber. In practice, the poskim are machmir and forbid בישול אחר בישול for a davar lach that has cooled. The Mechaber holds that if the davar lach has cooled to less than yad soledes bo, there is always an issur of bishul, even if it is still warm (שו”ע או”ח שי”ח ס”ד).
  • Rama. The Rama takes a position in the middle. He holds there is only an issur of bishul if the davar lach has completely cooled. Some say this issur is d’oraisa (מג”א סי’ רנ”ג סקל”ז), but most poskim hold that heating it is only assur d’rabanan even if it cooled completely (חזו”א או”ח סי’ ל”ז סקי”ג, שו”ת אג”מ ח”ד סי’ ע”ד בישול אות ב’ וה’, שו”ת מנחת שלמה ח”ב סי’ ל”ד אות כ”ג).
  • However, if the davar lach did not cool completely, there is no issur of bishul even if its temperature is below yad soledes bo (רמ”א שם סט”ו). “Not completely cooled” means that one can still eat/drink it in the capacity of a hot food/drink (שו”ע הרב ס”ט, אגלי טל האופה ס”ח, הגרשז”א, שש”כ ח”ג פ”א הע’ ט’).

Yaveish versus Lach

  • The poskim discuss at length the definitions of yaveish and lach regarding בישול אחר בישול, as well as the status of a food with both yaveish and lach components. This distinction determines whether a food may be heated on Shabbos at all. If something may not be heated and one wants to eat it hot, he must make sure it is hot from the start of Shabbos and on. We will first give some rules.

Majority Yaveish with Some Lach

  1. If a food is mostly yaveish with some lach, e.g., a slice of meat or cholent with only a little liquid, is it considered yaveish, in which case it can be heated in a permissible manner; or is it lach, in which case there is an issur of בישול אחר בישול if it cooled (see above, 6-7)? Some say we follow the majority – if the majority is yaveish, the whole thing is considered yaveish and may be reheated (מנחת כהן שער ב’ פ”ב, דעת תורה).
  2. However, many poskim argue. They hold that the liquid part is considered lach and may not be heated (א”ר סי’ שי”ח סקי”א, הגר”ז בסידורו, שו”ת חת”ס או”ח סוף סי’ ע”ד). If one wants to heat it, he must remove the food from the liquid [without violating the issur of borer]. Then, even if some liquid remains on the dry food, there is no problem since one is not interested in it.

Starts Off Yaveish, Becomes Lach

  1. The poskim also discuss foods that start off dry and solid but have parts that become liquid as they heat, e.g., a slice of cold meat with some congealed fat from sitting in the fridge. As it heats, juices and liquid fat ooze out. Does this have the status of lach based on how it will end up or do we only consider its current state, which would give it the status of yaveish regarding בישול אחר בישול?
  2. Meikel. Some allow heating it since it is yaveish when placed on the flame and there is no בישול אחר בישול for yaveish (מג”א סי’ שי”ח סוס”ק ל”א, סק”מ, שו”ת פנים מאירות ח”א סי’ פ”ד). When the fat is congealed, it looks like and is called a davar yaveish, so there is no issue of bishul whatsoever (שו”ת מנחת שלמה ח”ב עמ’ ל”ה).
  3. Machmir. Others say it has the status of a davar lach since it dissolves and then gets heated. Accordingly, it would be assur to heat it on Shabbos (לבוש סי’ שי”ח סט”ז, ט”ז סק”כ, מנחת כהן הובא בס’ שביתת השבת מלאכת מבשל בבא”ר אות פ”ה, שו”ע הגר”ז סוף ח”ב).
  4. In practice. Many poskim are meikel (מ”ב סי’ שי”ח סק”ק, חזו”א סי’ ל”ז סקי”ג). Thus, one may heat up a piece of meat with some congealed fat on top, for example, since the whole thing is considered yaveish. However, if there is a lot of congealed fat or gravy, one should not heat it up due to the issur of molid unless it is extremely necessary to do so (שו”ע סי’ שי”ח סט”ז).
  5. Instantly dissolve. It is proper l’chatchilah not to put something that dissolves immediately upon contact with a hot liquid, e.g., sugar, salt, or other powders, into a kli rishon even if it underwent a cooking process in the factory (מ”ב סי’ שי”ח סקע”א). Because the sugar dissolves right when it goes into the cup, it is only heated once it is already a liquid – this is considered bishul of a davar lach that cooled (שו”ת מהר”ם שיק או”ח סי’ קל”ב).

Yaveish Food with Some Moisture Inside

  1. Cooked foods that are essentially solid, just with some moisture absorbed within – e.g., all sorts of kugels; fine, cooked legumes or grains like rice; meatballs and fish patties; fried shnitzel with breadcrumbs; and the like – are considered yaveish. The fact that some juice or fat often oozes out when they are heated is irrelevant, as one has no interest whatsoever in this juice (קצוה”ש סי’ קכ”ד סט”ז, שו”ע הרב סי”ז, אגלי טל אופה סקנ”ה אות ד’, שו”ת שבט הלוי חי”א סי’ ס”ז, תשובות והנהגות ח”א סי’ ר”ז אות ה’).

Thick Consistency

  1. Ketchup, yogurt. Some treat a food with a thick consistency, e.g., ketchup, applesauce, yogurt, etc., as a davar lach (שו”ת אג”מ ח”ד סי’ ע”ד אות ה’); others treat it as yaveish (הגרשז”א). It is hard to pinpoint the exact thickness they were discussing. Thus, as long as, when one puts some of a certain substance on a plate and tilts the plate, it remains solid in its place and does not flow downward, it is considered yaveish.

Chocolate Soufflé, Molten Chocolate Cake

  1. A chocolate soufflé is a single-serving dessert baked for several minutes and then removed from the oven and served, such that the soufflé is completely baked on the outside but the chocolate inside is still soft and molten. When it cools, the chocolate inside hardens. If one wants to serve it hot, he reheats it, and the chocolate again softens and becomes runny. The question is, may one heat it in a permissible way on Shabbos? If it is considered yaveish, it is mutar; if it is lach, it is assur.
  2. Fully cooked. Is the chocolate in the middle considered fully cooked or not? It is possible that since that is how most people eat this dessert, it is considered “fully cooked” (ע”פ הר”ן שבת ל”ח. ד”ה ואי).
  3. Nolad. There is also no issur of nolad since the runny part is not visible on the outside, and nolad is not an issue for something that is not noticeable.
  4. Considered yaveish. In practice, there is also no problem of בישול אחר בישול. Before it is reheated, the chocolate is firm and solid; only after it is heated does it become runny. We already mentioned that most poskim hold we only look at the original state (above, 15), and there is no בישול אחר בישול for yaveish. Furthermore, even when it is runny, it has a thick consistency. Generally speaking, when the soufflé is flipped over, the chocolate does not drip down. Thus, even this can be considered yaveish, not lach (see above, 18).

Heating Foods on Shabbos

Issur of נתינה תחילה

  • On an actual flame. There is no heter to take a food that was not on a flame from before Shabbos and put it on a flame on Shabbos. This is true even if the flame is covered with a blech and there is no issur of bishul, e.g., a davar yaveish that was cooked before Shabbos, such as a kugel (above, 3). This issur is d’rabanan, because it looks like cooking (מ”ב סי’ שי”ח סקצ”ב). This is true of anything heated in a way that looks like cooking.
  • This is called the issur of “נתינה תחילה.” It is derived from the issur of chazarah: Even if something was on a flame, if one removed it and placed it on the floor, he may not return it to a flame because he might stoke the flame – certainly something that was not on a flame may not be placed on a flame to begin with.
  • Thus, one may not take food, e.g., kugel, cholent, shnitzel, etc., out of the refrigerator and put it directly onto a blech over the fire or onto an electric hot plate on Shabbos due to the issur of נתינה תחילה (הגרשז”א, מאור השבת ח”ב מכתב כ”ג ב’, הגריש”א שבות יצחק פ”ח).
  • B’dieved. If one mistakenly heated food on a covered flame on Shabbos, the food may not be eaten. However, if one b’dieved heated food on an electric hot plate designed to keep food warm and not typically cooked on, one can rely on the poskim who are meikel and hold the food is not assur (שו”ת אג”מ או”ח ח”ד סי’ ע”ד דיני בישול אות ל”ה, ארחות שבת פ”ב הע’ ק”ה).

Placing Food onto a Full Pot

  • Only davar yaveish. The poskim offer some ways to heat on Shabbos a davar yaveish that was cooked before Shabbos, as will be explained. However, it is important to stress that this is only for a davar yaveish; one may not heat a davar lach under any circumstances since we pasken יש בישול אחר בישול for a davar lach (above, 6-7).
  • One may put a cold, yaveish food, e.g., kugel, shnitzel, etc., on top of a full pot or hot water urn sitting on a flame or onto an electric kettle, even if the food being heated was not on any flame from before Shabbos. This is because it is not normal to cook something by putting it on top of a different pot (שו”ע סי’ רנ”ג ס”ה).
  • Inside a pot. However, one may not put food on Shabbos inside a pot of food sitting on a flame, e.g., by putting kugel wrapped in tinfoil into a pot of cholent on a flame. This is because everything inside the pot is considered to be on the flame, making it like נתינה תחילה on a flame (ארחות שבת פ”ב אות ס”ד).
  • Double pot. About thirty years ago, they came out with a new type of “double pot,” consisting of an upper pot encased in a lower pot, with the upper pot also serving as the cover for the lower one; there is a separate pot cover for the upper pot. It was designed to be able to cook in both pots simultaneously. The consensus of the poskim is that food may not be heated in the upper pot without meeting all the conditions of chazarah, as that is a normal way to cook during the week too. It is assur because it looks like cooking, as the upper pot is within the lower pot; it cannot be compared to heating food on top of a pot cover (מו”ר בשו”ת שבט הקהתי ח”ד סי’ ק”י).

Placing Food onto an Empty Pot

  • Open flame. Obviously, one may not put an empty pot on an open flame and put yaveish food inside to heat it – that is considered נתינה תחילה in the pot.
  • Also, one may not heat yaveish food on top of an empty pot’s cover or by putting a pot with food on top of an empty pot on an open flame. This looks like cooking, as the food is heated directly from the heat of the pot, which was heated on the flame. This is not like the heter of using a full pot (above, 28), where the food on top receives heat from the food inside the pot (ביאה”ל סי’ רנ”ג ס”ג סוד”ה ויזהר).
  • Covered flame. According to many poskim, though, if the flame is covered with a blech or if one is using an electric hot plate, he may put an empty pot on top and then heat yaveish food on top of the empty pot. This is because if the flame is already covered, the empty pot was put there to make a change in the manner of cooking, and there is a gap with airspace between the blech and the food on top of the pot, there is more room to be meikel, and one may put food on top of the pot (הגרשז”א, שש”כ ח”ג פ”א הע’ קיב, שו”ת שבט הלוי ח”א סי’ צא).
  • On an upside-down dish. If the flame is covered, one may also put an upside-down dish onto the blech/hot plate and heat on it yaveish food, e.g., challah, kugel, etc. This is not a normal way of cooking, so it does not have the status of נתינה תחילה.
  • Raised rack. Similarly, one may take a raised rack with small feet made for baking, place it so that is raised over a blech or hot plate, and put a yaveish food on it. This too is not a normal way to cook since there is airspace between the blech and the food. [They recently put out a special raised rack called “Al Plata,” with a hechsher from rabbanim, made to fit over hot plates of various sizes. Its purpose is to heat on top of it yaveish foods that were fully cooked before Shabbos. Incidentally, it also ensures that the food on the hot plate does not burn, thereby diminishing oneg Shabbos.] However, it is important to stress that there is no heter to use it for a liquidy dish, e.g., meat with lots of gravy or cholent. The whole heter is for yaveish foods, e.g., kugel, challah, schnitzel, or the like – not lach foods (see above, 6-7).
  • Setting up the empty/upside-down dish on Shabbos. It should be noted that when heating a yaveish food in the above ways – i.e., on an empty dish over a covered flame (33), on an upside-down dish (34), or on a raised rack (35) – most poskim allow setting up the upside-down dish or the rack on Shabbos. It does not need to be set up before Shabbos (שו”ת אג”מ או”ח ח”א סי’ צ”ג, הגרשז”א שו”ת מנחת שלמה ח”א סי’ י”א הע’ 2, שו”ת שבט הלוי ח”א סי’ צ”א).

Hot Plate on a Shabbos Clock

  • From Erev Shabbos. The poskim discuss whether one may put a fully cooked, yaveish food on a hot plate on Erev Shabbos to heat the food at the predetermined time on Shabbos when the hot plate will go on. Some allow this if the pot is there the whole time and is not moved from there at all before the hot plate goes on (חזו”א סי’ לז סכ”א וסי’ לח סק”ב).
  • Others forbid this (פסקי תשובות סי’ רנ”ג אות ל”א). Many poskim hold that one should not do this l’chatchilah so that he does not need to distinguish between different foods that are cooked and uncooked, besides for the many conditions needed to avoid issues of shehiyah and chazarah. Additionally, it can easily lead to disregard for Shabbos (שו”ת מנחת יצחק ח”ד סי’ כ”ו אות י’), unless it is only on occasion or for a mitzvah purpose, in which case one can go with the meikel opinion (מנח”י שם).

On Shabbos. However, if a hot plate on a Shabbos clock is set to go on, one may not put food on it on Shabbos even while it is off, and even if there is no issur of bishul, e.g., a fully cooked davar yaveish (חזו”א שם, שו”ת מנח”י שם, שו”ת אג”מ ח”ג סי’ כ’, הגריש”א מאור השבת ח”ד עמ’ קנ”ה הע’ ע”ח, ארחות שבת פ”ב סס”ח).

Zerachya Shicker is the translator for the English version of חוקי חיים. The Chukai Chaim is a halacha sheet in a league of its own. Started in August 2016 (Av 5776), the Chukai Chaim currently has a readership in the tens of thousands across the globe.

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