Arukh HaShulchan Yomi · Expert – Beit Midrash Analysis · Standard
Arukh HaShulchan, Orach Chaim 318:47-54
Sugya Map
The core of the sugya of Bishul Achar Bishul (cooking after cooking) on Shabbat lies in the metaphysical definition of the melakha of Bishul. Is Bishul defined by the physical, irreversible transformation of a substance’s material state, or is it defined thermodynamic-conceptually by the introduction of functional heat?
[Ontological Nature of Bishul]
|
+----------------------+----------------------+
| |
[Davar Yavesh (Dry)] [Davar Lach (Liquid)]
| |
Irreversible State Change Thermodynamic Heat State
| |
No Bishul Achar Bishul Is there Bishul Achar Bishul?
(Unanimous - Shabbat 145b) |
+------------------+------------------+
| |
[Rambam / MM] [Rashba / Rosh]
(Structural Change) (Thermodynamic State)
| |
No Bishul even if cold Yesh Bishul if cooled
- The Primary Issue: Whether the principle of Ein Bishul Achar Bishul (there is no cooking after cooking) applies universally to all physical states, or whether a fundamental divergence exists between Davar Yavesh (dry, solid food) and Davar Lach (liquid/fluid food).
- The Nafka Minot (Practical Ramifications):
- Reheating a completely cooled, previously boiled liquid (e.g., water, soup, or tea) on Shabbat.
- The status of a lukewarm liquid: Does it require Yad Soledet Bo (the threshold of scalding heat) to escape the prohibition of Bishul, or does any degree of residual warmth suffice?
- The status of Davar Gush (a solid mass of food) situated within a Kli Sheni (secondary vessel).
- Primary Talmudic Sources:
- Shabbat 145b: The foundational statement: "Kol she-ba b'chamim milifnei ha-shabbat, shorin oto b'chamim b'shabbat" (Anything that was processed in hot water before Shabbat may be soaked in hot water on Shabbat).
- Shabbat 40b: The limits of heating liquids and the status of Kli Sheni.
- Shabbat 34a: The prohibition of Chazarah (returning food to a heat source) and its intersection with Bishul.
Full Experience in the App
Listen. Chat. Go deeper.
Audio playback, interactive chevruta, Hebrew tools, and every daily learning track — only in Derekh Learning.
Text Snapshot
Let us examine the language of R. Yechiel Michel Epstein in Arukh HaShulchan, Orach Chaim 318:47:
"...דדבר יבש שנתבשל כל צרכו, אין בו משום בישול עוד אפילו נצטנן לגמרי... אבל בדבר לח שנצטנן, יש בו משום בישול... דבישול דלח אינו אלא לחמימותו, וכיון שנצטנן הלך לו הבישול הראשון, והוה ליה כמבשל עתה מחדש." [1]
Philological and Lomdishe Nuances
- "אין בו משום בישול עוד" (There is no longer any aspect of cooking): The Arukh HaShulchan uses the phrase mishem bishul od rather than simply mutar (permitted). This indicates that the physical act of cooking dry food has reached an ontological dead-end; the substance is fundamentally immune to further classification under the av melakha of Bishul.
- "דבישול דלח אינו אלא לחמימותו" (For the cooking of a liquid is nothing other than its heat-state): Note the precision of le-chamimuto. The Arukh HaShulchan does not say le-chummo (its heat), but le-chamimuto—a possessive noun indicating the state of being hot. For liquids, heat is not an accidental property (mikreh) of the cooked object; it is the essential form (tzurah) of its cooked state.
- "הלך לו הבישול הראשון" (The first cooking has departed): The verb halakh lo implies a spiritual or conceptual departure. When a liquid cools, the prior halakhic status of "cooked" does not merely become inactive; it is entirely evacuated from the cheftza (object).
Readings
To understand how the Arukh HaShulchan constructs his thesis in paragraphs 47–54, we must map out the landscape of Rishonim and Acharonim who govern this territory. This requires examining three distinct conceptual schools of thought regarding the nature of Bishul in liquids.
+---------------------------------------------------------------------------------------------------+
| THEORIES OF BISHUL IN LIQUIDS |
+-----------------------------------+-----------------------------------+---------------------------+
| Theory | Mechanism | Primary Proponents |
+-----------------------------------+-----------------------------------+---------------------------+
| 1. Structural / Ontological | Cooking permanently alters the | Rambam, Maggid Mishneh, |
| Transformation | substance; heat loss is secondary.| Arukh HaShulchan |
+-----------------------------------+-----------------------------------+---------------------------+
| 2. Thermodynamic State | Heat is the essence of liquid | Rashba, Rosh, Ran, |
| Equivalence | cooking; cooling resets status. | Shulchan Arukh |
+-----------------------------------+-----------------------------------+---------------------------+
| 3. Functional Warmth | Subjective utility; warmth | Rama, Ran (compromise) |
| (Lo Nitztenen Legamri) | preserves cooked status. | |
+-----------------------------------+-----------------------------------+---------------------------+
1. The Ontological School: Rambam and the Maggid Mishneh
The Rambam Mishneh Torah, Sabbath 9:3 writes:
"הַמְבַשֵּׁל עַל הָאֵשׁ דָּבָר שֶׁהָיָה מְבֻשָּׁל כָּל צָרְכּוֹ, אוֹ דָּבָר שֶׁאֵינוֹ צָרִיךְ בִּשּׁוּל כְּלָל—פָּטוּר." (One who cooks over a fire something that was fully cooked, or something that does not require cooking at all, is exempt). [2]
The Maggid Mishneh ad loc. understands this to mean that the Rambam does not distinguish between dry and liquid foods. Once a liquid has been boiled (nishtaleim bishulo), the act of cooking is complete, and subsequent heating cannot trigger a biblical violation of Bishul.
The Chiddush
According to this view, Bishul is defined by a singular, historic transformation of the substance. When water is boiled, it undergoes a halakhic transition from "raw" (chai) to "cooked" (mevushal). Although water does not change its physical shape like meat or dough, the initial boiling breaks its raw state.
Once this ontological boundary is crossed, the cheftza of the water is forever classified as mevushal. Reheating it, even if it has cooled to room temperature, is merely adding thermal energy to an already cooked substance. It lacks the chiddush (novelty) required to constitute the melakha of Bishul.
The Arukh HaShulchan in Arukh HaShulchan, Orach Chaim 318:48 champions this reading of the Rambam. He argues that the Rambam’s silence regarding any distinction between wet and dry items is deliberate. The Rambam views the physical transformation of the water’s molecular or halakhic structure as permanent.
To the Rambam, the heat is a byproduct of the process, not its definition. This is a radical conceptualization: it detaches the halakhic definition of "cooking" from the physical presence of heat.
2. The Thermodynamic School: Rashba, Rosh, and Ran
In contrast, the Rashba Rashba on Shabbat 40b s.v. Ha d'Amrinan and the Rosh Rosh on Shabbat 3:11 argue that liquids are fundamentally different from solids.
The Chiddush
For a solid (Davar Yavesh), cooking alters the physical structure of the food—softening meat, hardening an egg, or baking dough. This structural alteration is irreversible. Even when a steak cools down, it remains a cooked steak; it does not revert to raw meat. Therefore, Ein Bishul Achar Bishul applies because the physical transformation is permanent.
With liquids (Davar Lach), however, the entire purpose and expression of cooking is the heat itself. Water does not undergo a permanent structural change when boiled (at least none that Chazal recognize as halakhically significant for food preparation). When water cools down, it returns to its exact pre-boiled state.
Therefore, the Rashba argues, the cooling of a liquid is not merely a loss of temperature; it is the total undoing of its cooked status. When you reheat cold water, you are not continuing a previous state of cooking; you are initiating a brand-new act of cooking (mizdakeik le-bishul mishedash).
The Shulchan Arukh Shulchan Arukh, Orach Chaim 318:4 codifies this thermodynamic school:
"יֵשׁ בִּשּׁוּל אַחַר בִּשּׁוּל בְּדָבָר לַח, אִם נִצְטַנֵּן." (There is cooking after cooking in a liquid substance if it has cooled down). [3]
3. The Functional Compromise: The Rama and the Ran
The Rama Shulchan Arukh, Orach Chaim 318:4 introduces a critical qualification to the thermodynamic school, drawing from the Ran Ran on Shabbat 40b:
"וְדַוְקָא שֶׁנִּצְטַנֵּן לְגַמְרֵי, אֲבָל אִם לֹא נִצְטַנֵּן לְגַמְרֵי... מֻתָּר לְתִתּוֹ אֲפִילּוּ לְכַלִּי רִאשׁוֹן." (And this is specifically if it has cooled down completely, but if it has not cooled down completely... it is permitted to place it even into a primary vessel). [4]
The Chiddush
The Rama introduces a third conceptual model: Functional Warmth. If the liquid has not cooled down completely (lo nitztenen legamri), the original cooking has not been fully undone.
How do we define "not cooled down completely"? The Arukh HaShulchan Arukh HaShulchan, Orach Chaim 318:50 analyzes this deeply. He notes that some authorities require the liquid to still be at the temperature of Yad Soledet Bo (generally accepted as approx. 43°C–45°C) to be considered "not cooled."
However, the Rama holds that as long as the liquid retains some residual warmth and is still fit to be consumed as a warm beverage or food (re'uyah l'achilah/shtiyah מחמת חמימותו), the original Bishul remains intact.
This position suggests that Bishul in liquids is not a binary switch (either fully cooked or raw) but a spectrum of utility. As long as the liquid retains some of its functional warmth, the thermodynamic state of "cooked" is not entirely lost. Reheating it to a boil is viewed as a continuation of the existing state of warmth rather than a new act of creation (molid).
4. The Arukh HaShulchan’s Conceptual Synthesis
In Arukh HaShulchan, Orach Chaim 318:48-49, R. Yechiel Michel Epstein performs a masterclass in lomdus by reconciling these three positions. He poses a fundamental question: If the Rambam holds there is no cooking after cooking in liquids even if they are completely cold, why does the Shulchan Arukh rule so stringently?
The Arukh HaShulchan explains that the dispute hinges on whether we look at the action of the cook (gavra) or the result in the object (cheftza).
- According to the Rambam, the Torah prohibits the transformation of the food. Once the food has been transformed, the prohibition of cooking cannot be violated again, regardless of subsequent temperature drops. The act of heating a cold, previously boiled liquid does not perform any new structural transformation on the substance.
- According to the Rashba, the Torah prohibits the creation of a hot liquid state. Since a hot liquid state is transient, the act of heating a cold liquid is functionally identical to cooking raw liquid.
The Arukh HaShulchan notes that while we rule stringently like the Rashba on a biblical level (le-chumra d'orayta), we utilize the Rambam’s conceptual model to permit leniencies when the liquid is only partially cooled. This justifies the Rama’s ruling that lo nitztenen legamri is permitted.
Friction
The Core Kushya (Contradiction)
The primary friction in this sugya arises when we contrast the thermodynamic school’s treatment of liquids with the physical reality of boiled water.
The Rosh and Rashba argue that Yesh Bishul Achar Bishul applies to liquids because once a liquid cools, it returns to its original state. But is this physically or halakhically true?
We see explicitly in Shabbat 145b that water that has been boiled undergoes a permanent, irreversible change in its properties. Raw water contains gases and minerals that escape upon boiling. Chazal themselves recognize this!
In Eruvin 29b, the Gemara discusses Mayim Bishulim (cooked water) and notes its therapeutic and distinct physical properties compared to raw water. Boiled water is flatter, softer, and does not spoil as quickly as raw water.
If Chazal recognized that boiled water undergoes a permanent, irreversible change in its physical makeup, why does the thermodynamic school claim that when water cools, "the first cooking has departed" (halakh lo ha-bishul ha-rishon)?
If the physical change is permanent, it should be classified as a Davar Yavesh, and there should be no Bishul after Bishul!
[The Physical/Halakhic Contradiction]
|
+------------------------+------------------------+
| |
[Thermodynamic School] [Physical Reality]
Liquid cools -> returns to Boiled water is permanently
original state (Rosh/Rashba). altered (Eruvin 29b).
| |
+------------------------+------------------------+
|
[How to Reconcile?]
Terutz A: The Functional Definition of "State" (Arukh HaShulchan)
The Arukh HaShulchan Arukh HaShulchan, Orach Chaim 318:47 addresses this conceptual difficulty. He argues that the halakhic definition of Bishul does not track microscopic chemical changes, nor does it track subtle shifts in taste (like the flatness of boiled water). Instead, it tracks the functional utility of the substance for human consumption.
In dry foods, the physical transformation (softening, tenderizing, hardening) is what makes the food edible. A cold cooked steak is still edible as a cooked steak. The physical transformation is the primary vessel of its utility.
In liquids, however, the primary utility of cooking is the thermal energy itself. People do not boil water merely to make it "flat" or to release dissolved gases; they boil water to make it hot.
Therefore, even though the water has undergone a permanent chemical change, that change is halakhically irrelevant (batel) to the primary definition of Bishul for liquids, which is exclusively defined by temperature. When the temperature drops, the primary utility of the cooking is gone. Consequently, the halakhic status of "cooked" is lost.
Terutz B: The Brisker Analysis of Rav Chaim Soloveitchik
To deepen this resolution, we can apply the classic Brisker distinction between two aspects of Melakha: the Pe'ulah (the physical act of cooking) and the Kiyum (the resulting state of being cooked).
[Brisker Conceptual Split]
|
+------------------------+------------------------+
| |
[Pe'ulah] [Kiyum]
The physical action of The resulting state
introducing heat. of being cooked.
In Davar Yavesh, the Kiyum of Bishul is a physical change in the food's substance. Once that Kiyum is established, any subsequent Pe'ulah of heating is not a Kiyum of Bishul because the food cannot become "more cooked" than its fully cooked state.
In Davar Lach, the Kiyum of Bishul is not a physical change, but the thermodynamic state of heat. Because this state is transient, the Kiyum of Bishul exists only as long as the heat exists.
Once the liquid cools, the Kiyum of the first cooking is dissolved. Therefore, when you heat it again, you are performing a new Pe'ulah that creates a brand-new Kiyum of Bishul.
This explains why the chemical changes in the water do not prevent Bishul Achar Bishul. The chemical change is merely an accidental byproduct; the true halakhic Kiyum of Bishul in liquids is the heat itself.
Intertext
To fully grasp the mechanics of Bishul Achar Bishul, we must examine its intersection with two closely related halakhic principles: the transition between different cooking modalities, and the thermodynamic behavior of solid masses (Davar Gush).
1. The Intersection of Different Modalities: Cooking vs. Baking
In Arukh HaShulchan, Orach Chaim 318:51, R. Yechiel Michel Epstein addresses a parallel sugya that tests the boundaries of Bishul Achar Bishul:
"יש מי שאומר דבישול אחר אפייה וצלי... יש בו משום בישול... דאפייה וצלי אינו מועיל למקום בישול." (There are those who say that cooking after baking or roasting... is subject to the prohibition of cooking... because baking and roasting do not satisfy the requirements of cooking). [5]
This is based on the famous passage in the Yerushalmi Shabbat 3:5:
"האופה בישל? תני יש בישול אחר אפייה ויש אפייה אחר בישול." (Does one who bakes cook? It is taught: There is cooking after baking, and there is baking after cooking). [6]
The Conceptual Machinery
If Bishul Achar Bishul is governed purely by whether a substance has already been cooked, why should the method of cooking matter? If a loaf of bread is fully baked, it is fully processed. Why should placing that bread into a pot of hot soup constitute a biblical violation of Bishul?
The answer lies in the qualitative difference between Bishul (cooking via liquid medium) and Afiyah/Tzli (baking/roasting via dry heat).
[Modalities of Heat]
|
+-------------------------+-------------------------+
| |
[Bishul] [Afiyah/Tzli]
Moist heat (water-based) Dry heat (fire/air-based)
Softens fibers, infuses moisture Extracts moisture, hardens/crisps
- Bishul uses a liquid medium to soften fibers and infuse moisture.
- Afiyah/Tzli uses dry heat to extract moisture and harden or crisp the exterior.
Because these two processes achieve opposite physical results, they are categorized as distinct melakhot (or at least distinct sub-categories of the av).
The physical state achieved by baking is not the same as the physical state achieved by cooking. Therefore, when you take a baked item and cook it in liquid, you are performing a new physical transformation that the baking did not achieve.
This is why the Yerushalmi rules Yesh Bishul Achar Afiyah (there is cooking after baking). The Arukh HaShulchan notes that we rule stringently on this matter, which is why one must not put dry bread directly into a Kli Rishon of soup on Shabbat.
2. The Phenomenon of Davar Gush
In Arukh HaShulchan, Orach Chaim 318:52, the author tackles the status of a Davar Gush (a dense, solid mass of food, such as a hot potato or a piece of meat):
"דבר גוש, פירוש חתיכה גדולה וחמה... אפילו הוא בכלי שני, דינו ככלי ראשון כל זמן שהיד סולדת בו." (A solid mass, meaning a large, hot piece... even if it is in a secondary vessel, its status is like a primary vessel as long as it is hot enough to scald the hand). [7]
The Thermodynamic Mechanics
Normally, a Kli Sheni (the vessel into which food is poured from the cooking pot) cannot cook. The walls of a Kli Sheni are cold, which causes the liquid inside to cool rapidly, preventing the process of Bishul from occurring. This is the baseline rule of Shabbat 40b.
However, a Davar Gush does not behave like a liquid. Because of its density and lack of fluid circulation, it retains its internal heat even when placed into a cold Kli Sheni. The outer surface acts as an insulating barrier, keeping the core at cooking temperature.
[Thermodynamics of Davar Gush]
|
+-------------------------+-------------------------+
| |
[Liquid in Kli Sheni] [Davar Gush]
Rapid cooling due to fluid Heat retained internally;
convection & cold vessel walls. insufficient heat dissipation.
| |
Cannot cook (generally). Acts as Kli Rishon (can cook).
The Maharshal Yam Shel Shlomo, Shabbat 3:45 and the Rama Shulchan Arukh, Orach Chaim 318:15 rule that because a Davar Gush retains its heat, it behaves halakhically as a Kli Rishon. If you place raw spices or butter onto a hot potato sitting in a Kli Sheni, you violate the biblical prohibition of Bishul.
The Arukh HaShulchan Arukh HaShulchan, Orach Chaim 318:52 analyzes this with typical precision. He points out a major dispute: Does Davar Gush act as a Kli Rishon only to cook other things placed on it, or does it also retain its own susceptibility to being cooked?
He limits the stringency, noting that while we treat it as a Kli Rishon to be strict (le-chumra), we do not automatically apply all rules of Kli Rishon to it where it would lead to logical absurdities.
Psak/Practice
How does this complex web of conceptual models land in practical Halakha and modern kitchen practice?
1. The Sephardic vs. Ashkenazic Divide
The practical application of Bishul Achar Bishul in liquids is one of the most prominent halakhic divides between Sephardic and Ashkenazic Jews.
+---------------------------------------------------------------------------------------------------+
| PRACTICAL HALAKHIC COMPARISON |
+-----------------------------------+-----------------------------------+---------------------------+
| Metric | Sephardic Practice (Mechaber) | Ashkenazic Practice (Rama)|
+-----------------------------------+-----------------------------------+---------------------------+
| Reheating Cold Liquid | Strictly Prohibited (Biblical) | Strictly Prohibited |
| (e.g., Soup, Tea) | | (unless warm) |
+-----------------------------------+-----------------------------------+---------------------------+
| Lukewarm Liquid | Prohibited if below Yad Soledet Bo| Permitted if still warm |
| (Residual Warmth) | | enough to enjoy |
+-----------------------------------+-----------------------------------+---------------------------+
| Dry Food with Minor Liquid | Prohibited if liquid is dominant | Permitted if liquid is |
| (Davar Yavesh miza'ar) | | auxiliary / negligible |
+-----------------------------------+-----------------------------------+---------------------------+
- The Sephardic Practice (Following the Shulchan Arukh):
- If a liquid has cooled down below the temperature of Yad Soledet Bo, it is biblically prohibited to reheat it on a heat source on Shabbat.
- Therefore, one may not take cold soup or water from the refrigerator and place it onto a hot plate, warming tray, or any heat source on Shabbat.
- The Ashkenazic Practice (Following the Rama):
- If the liquid is still warm enough that one can derive pleasure from its warmth (lo nitztenen legamri), it may be reheated.
- Furthermore, if a dry food contains a tiny amount of moisture or grease that liquefies upon heating (e.g., cold chicken with congealed fat), the Ashkenazic practice is lenient. We view the liquid as auxiliary to the solid (Davar Yavesh miza'ar), and therefore Ein Bishul Achar Bishul applies.
2. Meta-Psak Heuristics of the Arukh HaShulchan
Throughout Siman 318, R. Yechiel Michel Epstein employs a specific meta-psak heuristic: The Preservation of Common Practice.
The Arukh HaShulchan is highly sensitive to the way simple Jews conduct themselves. When he encounters a widespread practice that seems to conflict with the strict rulings of the Shulchan Arukh, he does not immediately condemn it.
Instead, he uses his analytical framework to find conceptual justifications for the custom.
For example, in paragraph 50, he defends the practice of those who place cold water near a heat source where it can only reach a lukewarm state. He argues that since the water will never reach Yad Soledet Bo on that spot, the act does not constitute Bishul under any definition.
By distinguishing between Bishul (which requires reaching Yad Soledet Bo) and mere warming (Chimum), he provides a solid halakhic basis for common household conduct on Shabbat.
Takeaway
The laws of Bishul Achar Bishul reveal that halakhic cooking is not merely a physical event, but a conceptual classification.
For solids, cooking is an irreversible transformation of substance; for liquids, it is a transient state of thermodynamic utility.
References
- Arukh HaShulchan, Orach Chaim 318:47
- Mishneh Torah, Sabbath 9:3
- Shulchan Arukh, Orach Chaim 318:4
- Shulchan Arukh, Orach Chaim 318:4 (Gloss of the Rama)
- Arukh HaShulchan, Orach Chaim 318:51
- Yerushalmi Shabbat 3:5
- Arukh HaShulchan, Orach Chaim 318:52
derekhlearning.com