Shiur #02: Defining the Melakha of Bishul (Part 1)

  • Harav Baruch Gigi
The Israel Koschitzky Virtual Beit Midrash

The Laws of Shabbat
Yeshivat Har Etzion

Shiur #02: Defining the Melakha of Bishul (Part 1)

By Rav Baruch Gigi

Translated by David Silverberg



A. Cooking Foods


            The list of the thirty-nine melakhot – categories of activity forbidden on Shabbat – presented by the Mishna (Shabbat 73a) mentions the melakha of ofeh – baking.  As the Gemara notes, all the categories of melakha are based upon the activities performed in the Mishkan, and thus the Mishna should have chosen the term mevashel – cooking – rather than baking, since this melakha stems from the boiling of dyes during the construction of the Mishkan.[1]  The Gemara (Shabbat 74b) explains that the Mishna nevertheless preferred the term ofeh because it lists as melakhot the various stages in the preparation of bread (siddura de-pat).[2]  In any event, it emerges from this Gemara that both baking and cooking are forbidden on Shabbat; the prohibition also includes roasting, frying and smoking.[3]  In short, any action that renders a raw food item suitable for consumption, be it through water, oil or direct exposure to fire, constitutes a Torah violation of bishul.  This prohibition thus differs from basar be-chalav (cooking meat and milk together), regarding which it is unclear whether the Torah forbids roasting or frying, since the verse specifies cooking ("Lo tevashel gedi ba-chalev imo" – Shemot 23:19 and elsewhere).[4]  On Shabbat, by contrast, bishul is forbidden as part of the broader framework of the thirty-nine melakhot, regarding which the Torah prohibits any melekhet machashevet – intentional, constructive activity.  Hence, any form of food preparation is forbidden on Shabbat.


B. "Cooking" Metals and the Like


            It emerges from the Gemara's discussion (Shabbat 74b) that the bishul prohibition applies even to non-food items, such as metal and wax.  So long as we deal with foods, we can define the melakha as preparation the item for consumption.  With respect, however, to non-edible items, the Rambam writes (Hilkhot Shabbat 9:6):


One who melts any quantity of any kind of metal, or who heats the metal until it becomes a coal – this constitutes a tolada [derivative] of cooking.  Similarly, one who melts wax, fat, tar, lime, sulfur or something similar – this constitutes a tolada of cooking, and he is liable [to the death penalty].  Similarly, one who cooks earth utensils to the point where they become earthenware is liable for [the melakha of] cooking.  In sum, both burning a solid substance and solidifying a soft substance – one is thereby liable for [the melakha of] cooking.


The Rambam's formulation emphasizes two points:


  • One commits the violation by softening or solidifying a substance, even one that is not food.
  • The action must be performed specifically through fire.


We will discuss these two points and examine whether they are universally accepted, and their halakhic significance.  Here we will address the first question, and the second will be dealt with be"H in the next shiur.


Softening of Solidifying


            We begin with the following discussion in the Gemara (74b):


Rav Acha Bar Rav Avira said: One who casts a pin into an oven [for it to dry] is liable for mevashel.  Is this not obvious?  One would have thought that he intends to harden the tool; it therefore teaches that it is softened and only then contracts.  Rabba Bar Rav Huna said: One who boils lime is liable for mevashel.  Is this not obvious?  One would have thought that since it [ultimately] hardens again, perhaps [one is] not [liable]; it therefore teaches [otherwise].


It emerges from the straightforward reading of the Gemara that one violates Shabbat specifically by softening a substance, and not by hardening it.  This is also the implication of Rashi's comments to this passage.  Commenting on the term "li-sherurei" (to harden), he writes: "To make it hard – and this does not constitute bishul."  Then, Rashi cites the words "de-mirpa rafi" ("it is softened") and adds, "by the heat of the fire, and the water inside it leaves; after its water leaves, it 'contracts' – it hardens.  And when it is initially softened – this constitutes its bishul."


On this basis, the Lechem Mishneh questions the Rambam's view, that even solidifying a substance violates this prohibition.  He suggests the following explanation:


He maintains that any liquid that is cooked, even if it solidifies – one is liable for bishul, as it resembles baking.  And that which they said regarding a pin… one might have thought that no melakha is performed, since they are already hard, and they merely harden even more.  It therefore informs us that one is liable for bishul because the fire initially softens them and they become like liquid, and only then it hardens them.  For this reason, one is liable.  In all cases, however, one is liable for the hardening of any moist substance.


According to the Lechem Mishneh, since we find instances of the principal melakha – food preparation – involving both softening – such as cooking meat and vegetables – and hardening – such as baking bread – both these processes are likewise forbidden when dealing with non-food items.  The prohibition discussed in our sugya involves the hardening that takes place after the initial softening.


            It seems that most Rishonim[5] accept Rashi's interpretation, in accordance with the simple, straightforward reading of the Gemara.  We might claim, however, that even this position agrees fundamentally that hardening a substance likewise violates the prohibition, and Rashi's comments refer only to the specific case of a pin, which does not undergo a significant change when placed in the oven for additional hardening.  In a case, however, of baking clay so it becomes solid earthenware, Rashi would perhaps render one liable for bishul, as this process results in the clay's transformation into an actual utensil.[6]  In any event, the poskim adopted the Rambam's position, and one must therefore refrain from any action involving the hardening or softening of products through exposure to fire.


Drying Clothes Near a Fire


            The Mordekhai writes (Shabbat, 434), "We should forbid drying clothes [that had been] soaked in water near the fire on Shabbat, because of melaben [the melakha of laundering]… We should also forbid it because of mevashel, just like one who casts a pin into an oven, who is liable for mevashel."  It is difficult to understand the comparison drawn between drying clothes near a fire and the case of a pin.  Nevertheless, this halakha is codified in the Shulchan Arukh (O.C. 301:46): "It is forbidden to dry clothes that had been soaked in water near a fire."  Rabbi Akiva Eiger, in his glosses to the Shulchan Arukh, seems to have understood that the water absorbed in the garment is "cooked" by the heat of the fire.  This resembles the position of the Yerei'im and Piskei Ha-Rid, who explained the prohibition in the case of the pin as based upon the "cooking" of the moisture in the pin.  In my opinion, however, this explanation is very difficult to accept; the act of water evaporation, through which one makes no use of the "cooked" water, should not violate a Torah prohibition.  The Hagahot Mordekhai explains differently: "Anything that dries first softens as a result of the moisture inside it, and then hardens, as it says… 'One who casts a pin…'"  Meaning, the prohibition against drying an item through fire stems from the initial softening of the item, in accordance with Rashi's interpretation of the Gemara's discussion regarding heating a pin.  The Vilna Gaon (in Hagahot Ha-Gra) appears to explain this way, as well.[7]


C. The Relationship Between Cooking Foods and "Cooking" Metals


Bishul Achar Bishul


            As mentioned earlier, the category of bishul includes melting wax and metal.  The Acharonim agree that although regarding food products Halakha generally dictates, "Ein bishul achar bishul" – meaning, once an item has been cooked, repeated cooking does not constitute bishul – nevertheless, repeated melting of metals indeed violates the bishul prohibition.  Once the metal hardens after the initial melting, that initial melting is no longer taken into account at all, and we therefore consider the second melting equivalent to an initial melting.[8]  This does not apply, however, to repeated cooking of fat.  If one cooked fat to the point where it dissolved, and it then once again congealed, subsequent cooking would not constitute bishul, in accordance with the rule of ein bishul achar bishul.  Even after the fat congeals, it does not return to its previous condition before it was cooked, and we therefore take the initial cooking into account.  Indeed, the Kolbo rules explicitly that one may warm on Shabbat fat that had already been cooked, even after it congealed.


Hardening or Softening Foods


            The Kolbo further writes, "Rabbi David Ben Rabbi Levi wrote that perhaps even if oil had become solid as if it had been frozen from the cold, one may warm it, because warming it is not equivalent to cooking it, given that it is not initially intended to be frozen."  This position appears to maintain that melting an item that happened to have solidified constitutes a violation only if that item is meant to exist in a given chemical state which one now seeks to change.  Since oil is not meant to exist as a solid, one does not violate bishul by melting it.  According to this approach, we should forbid melting butter on Shabbat.  Even though butter begins as liquid milk, nevertheless, its natural state as butter is that of a solid.  Indeed, the work Kalkelet Ha-Shabbat (composed by the author of the Tiferet Yisrael commentary to the Mishna, as an introduction to the commentary to Masekhet Shabbat) rules that melting butter on Shabbat constitutes a Torah violation of bishul, as it entails softening a solid substance.  The work Shevitat Ha-Shabbat concurs.


            Rav Moshe Feinstein, by contrast, in Iggerot Moshe (O.C. 4:74, s.v. teshuva), seems to indicate otherwise.  He distinguishes between butter produced from pasteurized milk and from non-pasteurized milk, on the basis of the rule of ein bishul achar bishul, such that no prohibition would obtain when melting butter made from pasteurized milk.  Rav Moshe compares the status of butter in this regard to that of fat which was cooked and then congealed, which, as we cited earlier from the Kolbo, may be dissolved again[9], since it had already been cooked.  One may, however, question this comparison.  The fat had already been cooked before it dissolved; therefore, even after it congeals, dissolving it once again would amount to cooking a second time (bishul achar bishul), and should thus be permitted.  Butter, by contrast, has never been cooked as butter; the cooking occurred before the butter came into existence.  The Iggerot Moshe perhaps understood the Kolbo's ruling to mean that the prohibitions of softening and hardening – as we saw with regard to non-food items – do not apply at all to food products.  The rationale for such a position stems from our earlier discussion, where we noted that two distinct forms of bishul exist: preparing food for consumption, and softening or hardening an item through heat.  This distinction gives rise to the question of whether the bishul prohibition involving hardening or softening applies to foods.  This issue would affect cases of melting butter or cheese in soup or on a potato, on the one hand, and, on the other, making toast from slices of baked bread.  It thus appears that according to the Iggerot Moshe, bishul with respect to foods includes only preparation for consumption, and we may therefore apply the rule of ein bishul achar bishul even in cases of transforming a food item from solid to liquid, or vice-versa.


            Rav Ovadya Yosef addresses this issue in Yechaveh Da'at (3:22):


And even though the great author of Sho'el U-meishiv, in the Mahadura Telita'a (2:20), ruled that it is forbidden to place baked bread on the oven on Shabbat for it to further harden and become toast, bringing proof from the Rambam's ruling that one may not soften a hard item or harden a soft item, and here one transforms the soft bread into hard toast, nevertheless, even should we assume that we may equate the status of eggs with that of bread, it would still seem that the Sho'el U-meishiv's comments are not halakhically compelling.  The Rambam's comments, that it is forbidden to soften a hard item or harden a soft item, do not apply to food items, for it constitutes the standard manner of eating.  Just as one may soak dry bread in boiling soup to soften it, as the Kenesset Ha-gedola wrote (318:5), and as the great Maharsham also noted in his work Da'at Torah (318:5), that from the poskim's discussions plainly permitting baking a previously-baked item, it emerges clearly that there is no prohibition against hardening soft bread, and that the Rambam's comments forbidding the hardening of a soft item do not apply to foods, as this is the normal manner of consumption.


The lenient position perhaps maintains that softening or hardening foods that had already been cooked constitutes merely refinement, rather than actual cooking, and thus cannot render one liable.  This cannot be compared to melting metals or wax, which involves preparing the material for use in manufacture, for fashioning new utensils and the like.


            The work Shemirat Shabbat Ke-hilkhata (chapter 1, note 173) discusses this issue at length and presents the deliberations of Rav Shlomo Zalman Auerbach zt"l on the matter.  As for the final halakha, since we deal here with a question involving a Torah prohibition, such that according to the Shevitat Ha-Shabbat, Kalkelet Ha-Shabbat and Sho'el U-meishiv the Torah prohibition of bishul applies to softening or hardening food items, whereas the Iggerot Moshe and Yechaveh Da'at maintain that it does not, and Rav Shlomo Zalman Auerbach remained undecided on the matter, it would appear that one should endeavor to avoid melting butter and making toast on Shabbat.  Those who act leniently, however, have authorities on whom to rely.


D. Distinguishing Between Cooking and Kindling


            We will now turn our attention to the various rulings of the Rambam with regard to heating and melting metals.


            In Hilkhot Shabbat 9:6, he writes, "One who melts any quantity of any kind of metal, or who heats the metal until it becomes red hot as a coal – this constitutes a tolada [derivative] of cooking."  What is the difference between "melting" and "heating"?  One might have suggested that one who melts metal violates the prohibition of softening a solid item, whereas one who heats metal is liable for the heating itself, regardless of the softening.  (This would affect the question of whether kindling the filament in a light bulb constitutes bishul; there, too, the metal is not softened, but rather heated to the point where it becomes red hot.)  However, this explanation of the Rambam's comments seems difficult to accept, in light of his remarks in his commentary to the Mishna (7:2): "The concept of 'cooking' is the softening of hard objects, and therefore one who melts any metallic item or heats it – this is a derivative of [the melakha of] baking."  This passage suggests that both melting and heating stem from the prohibition against "softening hard objects."  We must therefore conclude that melting transforms the solid metal to liquid, whereas heating causes the material to soften, as the preparatory stage in the fashioning of the utensil.


            On this basis, we can perhaps explain another ruling of the Rambam, which many writers found difficult to understand (12:1): "One who kindles even a slight amount is liable [for Shabbat desecration]… One who heats iron in order to refine it with water – this constitutes a derivative of mav'ir [kindling], and he is liable."  The Ra'avad asks, "But why [is he not liable] for cooking, just like in the case of placing a pin in an oven, where it softens and then hardens?"  The Lechem Mishneh contends that the Rambam would hold one liable for both mav'ir and bishul in such a case.  However, the Rambam makes no mention of liability for bishul, and thus this understanding is difficult to sustain.  The more compelling approach in explaining the Rambam's position is that presented by the Chazon Ish (50:9), who distinguishes between different objectives in heating the metal.  If one softens the metal for the purpose of fashioning a utensil, then he performs the melakha of mevashel.  When, however, one intends to strengthen and harden a utensil, then he cannot be said to have violated mevashel, since he has no interest in softening the utensil, and this effect is of no significance to him.  Nor can we hold one liable in such a case for hardening a soft object, since the hardening of the iron occurs only through its exposure to water.  The Rambam therefore classifies this case only under the melakha of mav'ir.


            In chapter 9, the Rambam speaks of heating metal to the point where it becomes red hot, but yet he does not mention the melakha of mav'ir.  This can be understood once we consider the fundamental nature of mevashel.  A person can perform this melakha even by simply placing food on a fire and allowing it to cook, since this represents the standard manner of cooking.  The act of kindling, by contrast, is done with one's own hands.  The Rambam thus perhaps felt that only when one intends primarily to generate heat to refine the metal can we consider him as actively kindling the metal.  Where, however, his primary objective is to soften the metal, then we do not look upon the burning metal as the result of his actions, and we can thus hold him liable only for bishul, and not for mav'ir.


Halakhic Conclusions That Emerge from This Shiur


  1. On Shabbat one may not cook, fry, roast or bake food.
  2. One may likewise not melt metals or wax and the like, or solidify them.
  3. The poskim argue as to whether or not one may melt butter and yellow cheese, or make toast from bread.  One should preferably refrain from doing so, but those who are lenient have authorities upon whom to rely.
  4. One may not dry clothing on Shabbat by placing them near fire.


It should be noted that these halakhic conclusions are presented in brief, and are intended not as a comprehensive review of the entire shiur, but rather to help clarify the practical, halakhic issues discussed.




1.  The Gemara (74b) raises the question of why the Mishna refers to this melakha as ofeh – baking – rather than bishul – cooking, in light of the fact that it originates from the boiling of dyes during the construction of the Mishkan.  The Yerushalmi likewise poses this question, only with a different formulation, asking why the Mishna mentions baking, which is merely a tolada (derivative) of the principal melakha of bishul.  It is unclear whether the Bavli classifies ofeh as an av (principal melakha) or tolada.  The Rishonim debate this point, but their dispute concerns not only the specific issue of the halakhic relationship between baking and cooking, but rather a more fundamental question that relates to other melakhot, as well.  Namely, do we consider only the main activity the av, relegating all other actions to the status of tolada, or do we equate all parallel activities to the primary melakha, affording them all the status of av?  This question affects the relationship between cooking and baking, as well as that between planting seeds and planting saplings (zorei'a and notei'a).  Rabbenu Chananel (73b) follows the first approach, whereas Rashi (73b) and the Rambam (Hilkhot Shabbat, chapter 7) represent the second view.


2.  At first glance, it appears that this style of presentation is intended simply as a technique to help remember the melakhot, as it arranges them according to the sequence of preparing bread.  Perhaps, however, this reflects a more fundamental point, and the siddura de-pat process constitutes an essential theme of the list of melakhot.  See, for example, the Tosefta in Berakhot (Lieberman edition, chapter 6):

Adam Ha-rishon exerted himself so, and did not taste a single morsel until he planted, plowed, harvested, winnowed, threshed, separated [the kernels from the chaff], ground, sifted, kneaded and baked; only then did he eat.  But I arise in the morning and find all this ready for me.

            The perspective underlying the list of the melakhot perhaps relates to the basic activities required for human existence.  It should be noted that according to the Yerei'im, the Torah assigned the Sages the task of determining the various categories of forbidden activity on Shabbat.  Of course, this requires further elaboration in a separate context.


3.  The Yerushalmi (Shabbat 7:2) comments, "One who roasts, fries, boils and smokes – for all of them [he is liable] for mevashel."


4.  The poskim debate the issue of whether frying meat with milk constitutes a Torah violation; see Rashi and Tosefot, Sanhedrin 4b.  A similar question arises regarding roasting meat and milk; see Ran, Chulin 108a.


5.  From the comments of Tosefot, the Ramban and the Ritva to this sugya it appears that they followed Rashi's interpretation, that only softening a substance can violate the melakha of bishul.


6.  This is how the Minchat Chinukh explained Rashi's position (in the Mosakh Ha-Shabbat section).  One might, however, explain differently, that earthenware likewise first softens before hardening, and one is liable only for the initial softening.  Indeed, the Lechem Mishneh followed this understanding of Rashi's view, such that Rashi disagrees with the Rambam's position.


7.  I am uncertain whether this prohibition would apply to modern-day clothing.  True, according to Rabbi Akiva Eiger's understanding, attributing the prohibition to the "cooking" of the evaporating water, it should apply regardless of the type of clothing.  According to the Hagahot Mordekhai, however, that the problem lies in the softening and hardening of the garment, this perhaps applies only to the clothing in that time period, which was rougher than today's garments.  It is difficult to imagine modern-day clothing softening and hardening while drying near a flame.  The matter requires further study, but in any event, one certainly should avoid drying clothing near a fire, and not rely on this theoretical distinction.


8.  See Chazon Ish, 50:9; Har TzviTelalei Sadeh, ofeh, p. 262.


9.  He writes as follows: "Now butter in this country, which is produced from milk that is first boiled – called 'pasteurization' – if it had reached the point of yad soledet bo [the level of heat at which one's hand would instinctively recoil on contact], then the butter had been produced from cooked milk.  And since it had solidified, it is considered a dry food item, which is no longer subject to bishul, as mentioned explicitly in the Magen Avraham (40) with regard to congealed fat, which has now become like a solid and is no longer subject to bishul, and even if it dissolved and became liquid, it does not matter."