Arukh HaShulchan Yomi · Expert – Beit Midrash Analysis · Standard
Arukh HaShulchan, Orach Chaim 318:19-25
Sugya Map
The halachic parameters of Bishul (cooking) on Shabbat operate at the intersection of thermal physics, culinary convention, and formal legal taxonomy. The specific sugya analyzed by the Arukh HaShulchan in Arukh HaShulchan, Orach Chaim 318:19-25 addresses the boundary conditions of this Melacha. It maps out three distinct conceptual battlegrounds:
- Issue A: Bishul Achar Bishul (Cooking After Cooking) in Liquids (Lach). Does the cooling of a previously boiled liquid reset its halachic status, rendering subsequent reheating a Torah violation of Bishul?
- Nafkei Minot: Reheating fully cooked but cooled soup, pasteurized milk, or water.
- Primary Sources: Shabbat 34a, Shabbat 145b, Mishneh Torah, Sabbath 9:3, Shulchan Arukh, Orach Chaim 318:4.
- Issue B: The Taxonomic Status of Davar Gush (A Solid Hot Mass). Does a solid piece of hot food (e.g., a potato or meat) retain its status as a Keli Rishon (first vessel) even when resting inside a Keli Sheni (second vessel), thereby possessing the capacity to cook items placed upon it?
- Nafkei Minot: Sprinkling salt, spices, or pouring cold ketchup/gravy onto a hot baked potato or steak resting on a dinner plate.
- Primary Sources: Shabbat 40b, Shulchan Arukh, Orach Chaim 318:15, Maharshal (Yam Shel Shlomo, Shabbat, Ch. 3)[^1].
- Issue C: The Efficacy of Keli Shlishi (A Third Vessel). Does the halachic concept of Keli Sheni Eino Mevashel (a second vessel does not cook) extend to a Keli Shlishi as an absolute barrier against Bishul, even for Kalei HaBishul (easy-to-cook items)?
- Nafkei Minot: Brewing tea using tea bags, or adding raw spices to hot water poured from a cup into another cup.
- Primary Sources: Sefer Yereim (Siman 274)[^2], Mishnah Berurah 318:45, Arukh HaShulchan, Orach Chaim 318:24.
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Text Snapshot
To understand the analytical moves of the Arukh HaShulchan, we must examine his precise language. In paragraph 19, he frames the core debate of Bishul Achar Bishul in liquids:
"דעת הרמב"ם ז"ל... דבכל דבר לח שיש בו מרק או מים, אם נצטנן – יש בו משום בישול. ואף על פי שנתבשל כבר, כיון שנצטנן וחזר והרתיחו – הרי זה כמבשל מתחילה וחייב חטאת."[^3]
(The opinion of the Rambam, of blessed memory... is that regarding any liquid item that contains broth or water, if it has cooled down, the prohibition of cooking applies to it. Even though it was already cooked, since it cooled down and one reheated it to a boil, this is like cooking from the beginning, and he is liable for a sin-offering.)
Note the grammatical and conceptual precision of the word נצטנן (nitztanen - cooled down). The Arukh HaShulchan does not merely use the term to mean "ice cold," but rather to denote a state of transition where the liquid has lost its functional thermal identity.
In paragraph 23, he shifts his gaze to the thermodynamic reality of a Davar Gush:
"דבר גוש, כלומר חתיכה מוצקת שאין בה מרק, והיא חמה... יש מי שאומר דאפילו בכלי שני יש לה דין כלי ראשון... מפני שהדבר גוש מחזיק חמימותו זמן מרובה... אבל באמת דבר זה הוא נגד החוש, דחזינן בעינינו שאין להדבר גוש כח לבשל..."[^4]
(A solid mass, meaning a solid piece that has no broth, and is hot... there is one who says that even in a second vessel it has the status of a first vessel... because the solid mass retains its heat for a long time... but in truth, this matter is against sensory perception, for we see with our own eyes that a solid mass does not possess the power to cook...)
The phrase נגד החוש (neged he-chush - "against sensory perception" or "against empirical reality") is a critical methodological move. The Arukh HaShulchan consistently champions the integration of empirical reality (metziut) with formal halachic structures, refusing to let abstract legal formalisms completely detach from physical reality.
Readings
1. The Ontology of Liquid Cooking: Rambam vs. Rosh
The debate surrounding Bishul Achar Bishul in liquids hinges on a deep ontological question: What is the definition of "cooking"? Is it the permanent physical transformation of a substance (the chemical change), or is it the temporary thermal elevation of that substance?
The Rambam's Pure Thermal Model
The Rambam, in Mishneh Torah, Sabbath 9:3, rules that if a liquid has cooled down, reheating it constitutes a Torah violation of Bishul.
The conceptual basis for this is that liquids do not undergo a structural transformation when cooked. Unlike meat or dough, which change state from raw to cooked, water remains water. Its "cooked" status is defined solely by its thermal state (Yad Soledet Bo - hot enough that a hand recoils from it).
Once a liquid cools, its halachic status as "cooked" is erased. Therefore, reheating it is not merely warming it; it is a new act of Bishul (Mevashel mi-tchilah)[^5].
The Rosh's Structural Transformation Model
The Rosh Rosh on Shabbat 3:11 and the Rashba Rashba on Shabbat 39a argue that once a substance—solid or liquid—has been subjected to the heat of a Keli Rishon, the act of Bishul is complete. The physical properties of the water have been altered (e.g., boiled water is softer, or has been pasteurized/purified).
Subsequent cooling does not strip the liquid of its "cooked" identity. Reheating it, therefore, is a non-constructive act of mere warming, which does not violate the Torah prohibition of Bishul (Ein Bishul Achar Bishul).
The Arukh HaShulchan’s Synthesis
The Arukh HaShulchan Arukh HaShulchan, Orach Chaim 318:19-20 navigates this split by analyzing the exact threshold of nitztanen (cooling). The Shulchan Arukh Shulchan Arukh, Orach Chaim 318:4 rules strictly like the Rambam, while the Rama licenses reheating as long as the liquid has not cooled completely (she-lo nitztanen legamrei).
The Arukh HaShulchan introduces a brilliant psychological-empirical definition of "completely cold." He argues that "completely cold" does not mean room temperature. Rather, if the liquid is still warm enough that a person would drink it as a warm beverage without further heating, it is not considered nitztanen legamrei.
By defining the physical state through human utility (tashmish), he bridges the gap between the Rambam’s thermal model and the Rosh’s structural model. The identity of the food is determined by how it is perceived and used by human beings, not merely by a thermometer.
2. The Thermodynamics of the Solid Mass: Maharshal vs. Rama
The status of a Davar Gush (a hot, solid mass) represents a fascinating clash between the formalistic laws of Kelim (vessels) and the physical reality of heat transfer.
[Keli Rishon (On Fire)]
│
▼ (Pouring)
[Keli Sheni (Vessel)] ───► Standard Liquid: Cools rapidly due to vessel walls (No Bishul)
│
▼
[Davar Gush (Solid)] ───► Traps internal heat; behaves like Keli Rishon (Bishul potential)
The Maharshal's Physical Heat Retention Model
The Maharshal, in his Yam Shel Shlomo, asserts that a solid food item (like a hot potato or a piece of meat) does not behave like a liquid when poured into a Keli Sheni[^6].
The standard rule that Keli Sheni Eino Mevashel is based on the thermodynamic reality that the cold walls of the second vessel (dofnot ha-keli) absorb the liquid's heat, causing it to cool rapidly.
However, a Davar Gush is solid; it does not flow, and its outer boundaries act as an insulator, trapping its internal heat. Because its temperature remains high, the Maharshal rules that a Davar Gush retains the status of a Keli Rishon even when sitting in a Keli Sheni. It can cook spices or liquids placed upon it.
The Rama and the Acharonim
The Rama, in Shulchan Arukh, Orach Chaim 318:15, and the Taz Taz on Shulchan Arukh, Orach Chaim 318:13 accept the Maharshal’s stringency.
Consequently, one would be forbidden from putting butter, spices, or cold water onto a hot potato resting on a plate, as the potato would cook them.
The Arukh HaShulchan’s Deconstruction
The Arukh HaShulchan Arukh HaShulchan, Orach Chaim 318:23 mounts a devastating critique of this position. He argues that the Maharshal's model conflates two different halachic concepts: the power of heat (chumrat ha-chom) and the power of the vessel (koach ha-keli).
For Bishul to occur on a Torah level, the heat must be delivered via the agency of a vessel that was directly heated by fire (Koach Keli Rishon). A Davar Gush, once removed from the pot, is no longer associated with the fire-vessel agency.
Even if it is physically hot, its heat is passive. It lacks the Koach HaKeli to project its heat outward to transform another substance in a culinary fashion.
Furthermore, R. Epstein notes that "we see with our own eyes" that if you place a cold item on a hot potato, it does not become cooked in a culinary sense; it merely warms up.
Therefore, while he respects the Rama's stringency regarding raw spices (like pepper or salt), he strictly limits the definition of Davar Gush. He rules that it does not make the plate a Keli Rishon, and it cannot cook liquids or other fully cooked items placed next to it.
3. Keli Shlishi: Pure Halachic Formalism
In paragraph 24, the Arukh HaShulchan addresses the status of a Keli Shlishi (a third vessel, i.e., water poured from a kettle into a cup, and then poured from that cup into another cup).
The Yereim’s Thermodynamic Anxiety
The Sefer Yereim Sefer Yereim 274 expresses a deep anxiety regarding Kalei HaBishul (easy-to-cook items). He argues that if an item is physically easy to cook, it will cook in any vessel, even a Keli Sheni or a Keli Shlishi, as long as the water is Yad Soledet Bo.
The Mishnah Berurah Mishnah Berurah 318:45 heavily relies on this view, which leads to his famous stringency forbidding the brewing of tea with a tea bag on Shabbat, even in a Keli Shlishi.
The Arukh HaShulchan’s Formalist Masterstroke
The Arukh HaShulchan Arukh HaShulchan, Orach Chaim 318:24 rejects this stringency, defending the widespread custom (Minhag Yisrael) of brewing tea in a Keli Shlishi. He writes:
"ומעולם לא שמענו מי שפקפק בזה... ופוק חזי מאי עמא דבר."[^7]
(And we have never heard of anyone who doubted this... go out and see what the nation does.)
To justify this custom, he introduces a formalist model of Keli Shlishi. Halachic Bishul, he argues, is not a branch of physics; it is a legal taxonomy.
The Torah prohibited cooking in a Keli Rishon. The Sages extended this to a Keli Sheni out of concern for Kalei HaBishul.
However, they drew an absolute line at Keli Shlishi. Once heat has been transferred twice (kachash kecheshya - its strength has been weakened)[^8], the heat is halachically "broken."
Even if the water in a Keli Shlishi is physically scalding hot (above Yad Soledet Bo), it is legally categorized as eino mevashel (incapable of cooking). The physical heat is decoupled from the halachic category of Bishul.
Friction
Kushya 1: The Thermodynamic Paradox of the Modern Thermos
The classic definition of Keli Sheni assumes that the vessel's walls are cold and actively cool down the liquid. The Gemara in Shabbat 40b states: "דופנותיו קרושות" (its walls are cold).
This raises a massive difficulty: What is the status of a modern, highly insulated thermos?
Standard Keli Sheni:
[Hot Liquid] ───► [Cold Metal/Ceramic Walls] ───► Rapid Heat Dissipation (No Bishul)
Insulated Thermos (Keli Sheni):
[Hot Liquid] ───► [Vacuum/Insulated Walls] ───► No Heat Dissipation (Physical Cooking Continues)
If a thermos is used as a Keli Sheni (i.e., boiling water is poured from a kettle into a thermos), the vacuum-insulated walls do not absorb heat. The liquid inside can remain near boiling point for hours.
If physical heat retention is the mechanism that prevents a Keli Sheni from cooking, then a thermos should remain a Keli Rishon!
If, however, we apply pure formalism, the thermos is technically a Keli Sheni because it was not on the fire. How can we permit putting raw items into a thermos on Shabbat when we know, as a physical certainty, that they will cook?
Terutz A: The Chazon Ish's Thermodynamic Realism
The Chazon Ish Chazon Ish, Orach Chaim 52:19 rules that the halachic status of a vessel is determined by its physical function.
If a vessel is designed to prevent heat dissipation, the rule of Keli Sheni Eino Mevashel does not apply. Because the walls do not cool the liquid, it retains the halachic status of a Keli Rishon.
Therefore, one cannot put anything into a thermos of hot water on Shabbat, as it constitutes Bishul de-Oraita.
Terutz B: The Arukh HaShulchan’s Formalist Taxonomy
The Arukh HaShulchan Arukh HaShulchan, Orach Chaim 318:22 implicitly rejects this realistic collapse of the category. He argues that the Sages established the categories of Keli Rishon and Keli Sheni as absolute legal definitions (lo plug - they did not make distinctions).
The status of Keli Rishon is reserved exclusively for a vessel that has a direct relationship with the fire (koach ha-ur). Once a liquid is separated from that fire-vessel nexus, it enters the domain of Keli Sheni, regardless of the vessel's material or insulation properties.
The halachic definition of cooking requires the action of cooking in a manner aligned with the creative work of the Mishkan (Melechet Machshevet). Cooking in a highly insulated second vessel lacks the formal structure of Derech Bishul (the standard way of cooking).
Thus, the Arukh HaShulchan would maintain the formal category: a thermos is a Keli Sheni, and Keli Sheni Eino Mevashel applies, even if the physical heat is maintained.
Kushya 2: The Davar Gush Contradiction in the Rambam
A profound internal contradiction appears when we juxtapose the Rambam’s rulings on Bishul in liquids and solids.
- In Mishneh Torah, Sabbath 9:3, the Rambam rules that if water cools down, reheating it is a Torah violation (Yesh Bishul Achar Bishul be-Lach).
- In Mishneh Torah, Sabbath 22:8, the Rambam rules:
"אמבטי שהיא מלאה מים חמים... אין נותנין לה מים צונן מרובין... אבל נותן הוא מים חמים לתוך צונן או צונן לתוך חמים." (A bath that is full of hot water... one may not add a small amount of cold water... but one may pour hot water into cold, or cold into hot.)
How can the Rambam allow pouring cold water into hot water? If the cold water is warmed to Yad Soledet Bo by the hot water, and the Rambam holds Yesh Bishul in liquids, this should be a Torah violation of Bishul!
Terutz A: The Rav Chaim Soloveitchik Distinction (Gavra vs. Cheftza)
In his Chiddushei Rabbeinu Chaim HaLevi[^9], Rav Chaim resolves this by splitting the definition of Bishul. He argues that there are two distinct components to the Melacha of Bishul:
- The Action (Ma'aseh Bishul): The human act of placing food into a cooking environment.
- The Result (Toledat Bishul): The physical transformation of the food.
For solids, the Torah prohibits the result: as long as the food becomes cooked, the person is liable, regardless of how it happened.
For liquids, however, because there is no permanent structural transformation, the Torah only prohibits the Ma'aseh of cooking when it is done in a conventional manner (Derech Bishul), such as placing a vessel on a fire.
When one pours cold water into hot water, the heating of the cold water is a passive result of mixing (Keli Sheni or Irui), not a formal Ma'aseh of cooking. Thus, the Rambam permits it because it lacks the formal action of Bishul, even though the liquid physically heats up.
┌─────────────────────────────────────┐
│ Melachat Bishul on Shabbat │
└──────────────────┬──────────────────┘
│
┌────────────────────────┴────────────────────────┐
▼ ▼
┌───────────────────────┐ ┌───────────────────────┐
│ Solid (Yavesh) │ │ Liquid (Lach) │
├───────────────────────┤ ├───────────────────────┤
│ Focus: Result │ │ Focus: Action │
│ (Physical Change) │ │ (Standard Cooking) │
│ │ │ │
│ Any heat source that │ │ Only forbidden via │
│ transforms the food │ │ a formal "Ma'aseh" │
│ violates the Melacha. │ │ (vessel on fire). │
└───────────────────────┘ └───────────────────────┘
Terutz B: The Arukh HaShulchan’s Volumetric Mitigation
The Arukh HaShulchan Arukh HaShulchan, Orach Chaim 318:20 offers a highly pragmatic resolution. He explains that the Rambam only permits pouring cold water into hot water under two conditions:
- The hot water is in a Keli Sheni, where the capacity to cook is halachically neutralized.
- Or, if it is in a Keli Rishon, the volume of cold water must be so large that it completely cools down the hot water, preventing any Bishul from taking place.
If, however, a small amount of cold water is poured into a hot Keli Rishon such that the cold water is heated to Yad Soledet Bo, the Rambam would indeed hold him liable for a sin-offering. This realistic, volumetric approach avoids the need for abstract metaphysical splits, grounding the halacha in practical kitchen physics.
Intertext
To fully appreciate the Arukh HaShulchan's contribution, we must contrast his work with his great contemporary, R. Yisrael Meir Kagan (the Chafetz Chaim), in the Mishnah Berurah.
| Issue | Mishnah Berurah's Ruling | Arukh HaShulchan's Ruling | Conceptual Split |
|---|---|---|---|
| Tea in a Keli Shlishi | Stringent. Forbids tea bags; fears they are Kalei HaBishul and cook in Keli Shlishi Mishnah Berurah 318:45. | Lenient. Permits tea bags; argues Keli Shlishi is a formal zone of immunity Arukh HaShulchan, Orach Chaim 318:24. | Realism vs. Formalism. MB fears physical heat; AH champions formal legal boundaries and Minhag. |
| Ketchup on Davar Gush | Stringent. Treats hot meat/potatoes as a Keli Rishon; forbids placing ketchup on them Mishnah Berurah 318:65. | Lenient. Restricts Davar Gush to raw spices; permits ketchup/gravy on hot food Arukh HaShulchan, Orach Chaim 318:23. | Thermodynamics vs. Utility. MB focuses on heat retention; AH focuses on empirical impact. |
The Sephardic Parallel: The Ben Ish Chai
A fascinating cross-cultural alignment exists between the Lithuanian Arukh HaShulchan and the Baghdadi master, R. Yosef Chaim, in his Ben Ish Chai.
In Ben Ish Chai, Year 2, Bo 5, the Ben Ish Chai also discusses the status of Keli Shlishi and Davar Gush. Like the Arukh HaShulchan, the Ben Ish Chai defends the widespread custom of brewing tea in a Keli Shlishi.
However, their justifications differ. While the Arukh HaShulchan relies on the formal weakening of heat in a third vessel, the Ben Ish Chai argues that tea leaves are not Kalei HaBishul because they require prolonged boiling on a fire to release their flavor fully.
Thus, the Ashkenazi formalist (Arukh HaShulchan) and the Sephardic posek (Ben Ish Chai) arrive at the same lenient practical conclusion, but through different conceptual pathways.
Psak/Practice
How do the rulings of the Arukh HaShulchan in Arukh HaShulchan, Orach Chaim 318:19-25 manifest in a modern halachic kitchen?
1. The Ladle Dilemma
When serving hot soup from a pot sitting on a hotplate (Keli Rishon), what is the status of the ladle?
The Arukh HaShulchan Arukh HaShulchan, Orach Chaim 318:25 rules that if the ladle is left in the pot for a few moments, it achieves thermal equilibrium with the pot and becomes a Keli Rishon.
Therefore, pouring from that ladle directly onto raw food (like scallions in a bowl) would violate Bishul.
However, if the ladle is dipped in and immediately poured out, it acts as a Keli Sheni (or at least Irui Keli Rishon), mitigating the severity of the heat transfer.
Ladle Left in Pot:
[Keli Rishon Pot] ───(Heat Transfer)───► [Ladle becomes Keli Rishon] ───► Cooks raw food in bowl
Ladle Dipped and Poured Immediately:
[Keli Rishon Pot] ───(Immediate Pour)───► [Ladle acts as Keli Sheni] ───► Does not cook raw food
2. Soup Croutons and Soup Nuts
Can one add croutons or soup nuts to a hot bowl of soup on Shabbat?
According to the Arukh HaShulchan, since the soup was poured from the pot into a bowl, the bowl is a Keli Sheni.
Because Keli Sheni Eino Mevashel, one may add croutons.
Furthermore, even if the soup contains a Davar Gush (like a hot potato), the surrounding liquid circulates and cools the outer layer, neutralizing the Davar Gush status and allowing croutons to be added without concern.
3. Condiments on Hot Meat
Can one squeeze fresh lemon juice or pour cold ketchup onto a hot piece of chicken resting on a plate?
Under the strict interpretation of the Mishnah Berurah, this is forbidden because the chicken is a Davar Gush (acting as a Keli Rishon).
However, based on the Arukh HaShulchan’s ruling Arukh HaShulchan, Orach Chaim 318:23 that a Davar Gush lacks the Koach HaKeli to cook liquids or pre-processed foods, this is entirely permissible. The ketchup is merely warmed, not cooked.
Takeaway
The Arukh HaShulchan shifts the paradigm of Shabbat cooking from raw thermodynamics to halachic taxonomy. He establishes that the laws of Bishul are governed by formal legal structures (Keli categories) and empirical common sense, protecting the joy of Shabbat from over-stringency.
References
[^1]: R. Solomon Luria, Yam Shel Shlomo, Tractate Shabbat, Chapter 3, Siman 1. [^2]: R. Eliezer of Metz, Sefer Yereim, Siman 274. [^3]: Arukh HaShulchan, Orach Chaim 318:19. [^4]: Arukh HaShulchan, Orach Chaim 318:23. [^5]: See Mishneh Torah, Sabbath 9:3 s.v. "המבשל מים". [^6]: Yam Shel Shlomo, Shabbat 3:1. [^7]: Arukh HaShulchan, Orach Chaim 318:24. [^8]: See Shabbat 40b regarding the weakening of heat in successive vessels. [^9]: R. Chaim Soloveitchik, Chiddushei Rabbeinu Chaim HaLevi, Hilchot Shabbat, Chapter 9, Halacha 3.
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