Arukh HaShulchan Yomi · Expert – Beit Midrash Analysis · Standard
Arukh HaShulchan, Orach Chaim 318:41-46
Sugya Map
The halakhic boundaries of Bishul (cooking) on Shabbat are defined not merely by thermal intensity, but by the taxographical status of the vessel container. The transition of heat from a direct source of fire (Keli Rishon) to subsequent vessels (Keli Sheni and Keli Shlishi) forms the conceptual battleground of this sugya.
At the center of this analysis is the Arukh HaShulchan Arukh HaShulchan, Orach Chaim 318:41-46, which systematically categorizes the thermodynamic and formalist mechanics of these vessels.
[ Fire / Heat Source ]
│
( Keli Rishon ) ──> Cooks all materials
│
[ Transfer of Liquid/Solid ]
│
( Keli Sheni ) ──> Eino Mevashel (Except Kalei HaBishul)
│
[ Transfer of Liquid/Solid ]
│
( Keli Shlishi ) ─> Complete immunity from Bishul
The Core Issues
- The Mechanism of Keli Sheni: Why does a Keli Sheni (second vessel) not cook (eino mevashel), even if its temperature is physically identical to a Keli Rishon? Is this phenomenon thermodynamic (based on physical cooling) or formalist (based on the absence of direct fire-force, koach ha-esh)?
- The Definition of Kalei HaBishul (Easily Cooked Items): If Keli Sheni is generally unable to cook, why are certain items (kalei habishul) still susceptible? How do we identify these items in an era of halakhic uncertainty (anenu beki'in)?
- The Status of Keli Shlishi (Third Vessel): Does the halakhic category of Keli Sheni extend ad infinitum to a Keli Shlishi, or does a third vessel offer absolute immunity from the laws of Bishul?
- The Problem of Davar Gush (Solid Hot Mass): Does a solid piece of food (e.g., a potato or meat) retain its status as a Keli Rishon even when placed inside a Keli Sheni, because it lacks the convective cooling properties of liquids?
Nafka Mina (Practical Ramifications)
- Croutons and Spices: May one place uncooked croutons, salt, or spices into a bowl of hot soup?
- Tea and Coffee: Is it permissible to prepare tea or instant coffee using water from a Keli Sheni or Keli Shlishi?
- Condiments on Meat: Can one spread mustard, ketchup, or butter on a hot baked potato or a piece of roast chicken directly on one's plate?
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Text Snapshot
To understand the Arukh HaShulchan’s revolutionary synthesis, we must examine his precise language in Orach Chaim 318:41 and 318:44.
דע שכל זמן שהכלי על האש, ואפילו לאחר שהסירוהו מן האש כל זמן שהיד סולדת בו, נקרא "כלי ראשון"... אבל כשהקבו מן הכלי ראשון לתוך כלי אחר, נקרא כלי זה "כלי שני". וכלי שני אינו מבשל, ואפילו הוא חם ביותר שהיד סולדת בו. והטעם בזה: לפי שהכלי ראשון, מפני שהיה על האש, דפנותיו חמות ומחזיקות חמימותו זמן מרובה, ולפיכך הוא מבשל. אבל כלי שני, אף על פי שהמים שבו חמים, מכל מקום כיוון שדפנותיו קרין – הולך המים ומתקרר, ואין כוח בדפנות קרין לבשל.
— Arukh HaShulchan, Orach Chaim 318:41[^1]
דע שיש בזה דין גדול, והוא: דכל מה שנתבאר דכלי שני אינו מבשל, זהו דווקא בדבר לח... אבל דבר גוש, והיינו דבר יבש וקשה, כמו חתיכת בשר או תפוח אדמה וכיוצא בהם – יש אומרים דדינו ככלי ראשון כל זמן שהיד סולדת בו, ואפילו הוא בתוך כלי שני או שלישי... מפני שאינו מתקרר כל כך מהר מפני עביו וקשיותו.
— Arukh HaShulchan, Orach Chaim 318:44[^2]
Linguistic Nuances
- "דפנותיו קרין" (Its walls are cold): The Arukh HaShulchan emphasizes the physical state of the vessel's walls (dofnot). The transition from Keli Rishon to Keli Sheni is not just a nominal change of containers; it is a thermodynamic shift. The cold walls of the second vessel continuously extract heat from the liquid, disrupting the stability required for gmar bishul (the completion of cooking).
- "דבר גוש" (A solid mass): Note the shift from fluid dynamics to solid-state physics. The Arukh HaShulchan defines davar gush by its physical properties: density (עוביו) and solidity (קשיותו). The lack of convective movement within a solid prevents the cold walls of the vessel from cooling its core, creating a localized thermodynamic sanctuary that behaves like a Keli Rishon.
Readings
The debate over Keli Sheni and Davar Gush represents a fundamental split in how halakhists conceptualize physical processes. We can divide the major readings of this sugya into three schools of thought: the Thermodynamic School, the Formalist School, and the Arukh HaShulchan's Dialectical Synthesis.
┌─────────────────────────┐
│ MODELS OF BISHUL │
└────────────┬────────────┘
│
┌───────────────────────┴───────────────────────┐
▼ ▼
[ Thermodynamic Model ] [ Formalist Model ]
- Based on physical heat transfer - Based on halakhic categories
- Heat retention is key - Fire-force (Koach Rishon) is key
- Cold walls (Dofnot Karot) cool - Transfer of vessel breaks status
- Davar Gush = Keli Rishon - Davar Gush = Keli Sheni
1. The Thermodynamic School (Tosafot and the Maharshal)
The Thermodynamic School posits that the laws of Bishul on Shabbat are directly bound to physical reality. If an object is hot enough to cook, and its heat is sustained, it cooks halakhically.
- Tosafot’s Physical Thesis: Tosafot Shabbat 40b, s.v. "U'shma mina"[^3] raise the obvious question: if a Keli Sheni is scalding hot (yad soledet bo), why does it not cook? They answer that the physical walls of a Keli Sheni are cold (dofnot mitkarrot). This coldness immediately initiates a cooling process. Because the liquid is actively losing heat to its environment, it lacks the sustained energy required to break down the cellular structure of food. Cooking requires not just high temperature, but a stable or rising thermal trajectory.
- The Maharshal’s Solid-State Corollary: Based on this thermodynamic reading, the Maharshal (Yam Shel Shlomo, Pesachim 2:25)[^4] introduces the stringency of Davar Gush (a solid hot mass). If the reason a Keli Sheni does not cook is because its cold walls cool the liquid, this logic fails for solids. A hot potato or a piece of meat does not adapt to the shape of its container; it only touches the cold walls of the Keli Sheni at minimal contact points. Furthermore, because it is dense and lacks fluid circulation, its core temperature remains high. Therefore, the Maharshal rules that a solid mass retains its status as a Keli Rishon even when placed in a Keli Sheni or Keli Shlishi. It remains capable of cooking other items (like butter or cold gravy) as long as it is yad soledet bo.
2. The Formalist School (The Rashba and the Shach)
The Formalist School argues that Bishul on Shabbat is not a branch of thermodynamics, but a formal halakhic category. The prohibition of cooking is defined by Koach Rishon—the direct force of the fire.
- The Rashba’s Category Thesis: The Rashba Shabbat 40b, s.v. "Ha d'Amrinan"[^5] implies that once food is removed from the Keli Rishon, the direct connection to the creative force of fire (tashmish shel esh) is broken. The halakhic category of "cooking" requires a specific type of heat source: one that is either on the fire or in the vessel that sat on the fire. Once transferred, the liquid enters a new halakhic status (Keli Sheni), which is formally defined as incapable of cooking, regardless of its actual Celsius temperature.
- The Shach’s Rejection of Davar Gush: The Shach Yoreh Deah 105:8[^6] strongly opposes the Maharshal's application of Davar Gush to the laws of cooking. He argues that once a food item is transferred to a Keli Sheni, the formal category of Keli Sheni applies to the entire contents of that vessel, whether liquid or solid. Halakha does not calculate localized thermodynamic pockets inside a plate. A potato on a plate is in a Keli Sheni, and therefore, it cannot cook. The Shach concedes that we may be stringent with Davar Gush regarding the absorption of non-kosher flavors (Beli'ah in Hilchot Kashrut), but rejects its application to the creative labor of Bishul on Shabbat.
3. The Arukh HaShulchan’s Dialectical Synthesis
Rav Yechiel Michel Epstein Arukh HaShulchan, Orach Chaim 318:41-46 offers a brilliant synthesis of these two schools, distinguishing between liquid dynamics and solid-state heat retention, while maintaining a strict formalist boundary for Keli Shlishi.
┌────────────────────────────────────────┐
│ Arukh HaShulchan's Vessel Taxonomy │
└──────────────────┬─────────────────────┘
│
┌───────────────────────────┼───────────────────────────┐
▼ ▼ ▼
[ Keli Rishon ] [ Keli Sheni ] [ Keli Shlishi ]
- Retains fire-force - Active cooling by walls - Absolute thermal decay
- Cooks all things - Cooks Kalei HaBishul only - No cooking possible
- Davar Gush remains KR - Davar Gush remains KR - Even Davar Gush is lenient
The Physics of the Vessel (318:41): The Arukh HaShulchan adopts Tosafot’s thermodynamic explanation (dofnot mitkarrot) but elevates it to a formal halakhic principle. The coldness of the walls is not just an accidental physical property; it defines the halakhic essence of Keli Sheni. Because the vessel was never on the fire, its walls are "foreign" to the heat, creating an environment of thermal decay.
The Absolute Limit of Keli Shlishi (318:43): This is where Rav Epstein's genius shines. He addresses the view of the Pri Megadim and others who wanted to treat Keli Shlishi with the same stringencies as Keli Sheni (forbidding kalei habishul in it). The Arukh HaShulchan rejects this:
"But in truth, this is astonishing... for if so, there is no end to the matter! Shall we forbid a fourth and fifth vessel? Rather, the truth is that the Sages only drew a distinction between Keli Rishon and Keli Sheni. By the time it reaches a Keli Shlishi, the heat has been weakened twice over, and it has lost all power to cook, even for easily cooked items."[^7]
Here, the Arukh HaShulchan uses a thermodynamic reality (the exponential decay of heat with each transfer) to establish a formalistic, absolute boundary: Keli Shlishi does not cook, period.
The Nuanced View of Davar Gush (318:44-45): Rav Epstein accepts the Maharshal's physical model of Davar Gush but limits its scope. He recognizes that a solid mass does not cool down like a liquid. However, he notes that this is only true if the Davar Gush is dense and solid throughout. If it is soft, porous, or mixed with liquid, it cools rapidly and loses its Keli Rishon status.
Connecting to Rosh Chodesh Av
As we enter Rosh Chodesh Av and begin the Nine Days of mourning for the destruction of the Beit HaMikdash, we can find a deep spiritual parallel to this thermodynamic debate.
The fire that consumed the Temple was a Keli Rishon of destruction—a direct, intense manifestation of divine judgment. In our long exile, we find ourselves in the equivalent of a Keli Sheni or Keli Shlishi. The "walls" of our surrounding world are cold (dofnotav karot), and we feel a spiritual chill, far removed from the original fire of the Altar.
Yet, the Arukh HaShulchan’s analysis of Davar Gush teaches us a profound lesson. A solid, dense mass of faith—an unbreakable core of Jewish identity—retains its inner warmth (yad soledet bo) even when placed in the cold vessels of exile. It does not yield its heat to the cold walls of its environment. Like the Davar Gush, the Jewish soul maintains its internal fire, resisting the cooling forces of history.
Friction
The sugya of Keli Sheni and Davar Gush is filled with conceptual tensions. Let us explore the two strongest kushyot (difficulties) and their resolutions.
Kushya 1: The Paradox of Temperature vs. Category
If the reason a Keli Sheni does not cook is physical (because its cold walls cool the liquid, dofnot mitkarrot), then what should we do if we heat the walls of the Keli Sheni before pouring the hot liquid into it? Or, conversely, what if we have a Keli Rishon that has cooled down significantly but is still technically yad soledet bo (e.g., 45°C), while a Keli Sheni is scalding hot (e.g., 90°C)?
If thermodynamics is the sole metric, the 90°C Keli Sheni should cook, and the 45°C Keli Rishon should not. Yet, halakha rules the exact opposite: the Keli Rishon cooks, and the Keli Sheni does not!
[ Scenario A: Keli Rishon ] ──> 45°C (Yad Soledet) ──> Halakhically Cooks!
[ Scenario B: Keli Sheni ] ──> 90°C (Scalding) ──> Halakhically Does NOT Cook!
The Resolution (The Pri Megadim and Arukh HaShulchan)
To resolve this, we must understand that the Sages did not create a system of ad-hoc thermodynamic measurements for every kitchen. Instead, they established formal categories based on typical physical behaviors (lo natnu chachamim et divreihem l'shiurin).
The Pri Megadim Mishnab Berurah 318:41[^8] explains that a Keli Rishon possesses Koach Rishon—the momentum of the fire. The heat in a Keli Rishon is "aggressive" because it was generated in that very vessel while it was connected to the source of heat. This gives the molecules a cooking potency that persists even as the temperature drops.
Conversely, the heat in a Keli Sheni is "defensive" or "broken" (esh keshura). The act of pouring (iruy) breaks the thermal momentum, and the cold walls of the new vessel permanently alter its halakhic character.
Thus, the Arukh HaShulchan Arukh HaShulchan, Orach Chaim 318:41 explains that even if you preheat the walls of a Keli Sheni, it remains halakhically a Keli Sheni. The Sages' definitions are absolute formal categories based on the mechanism of heat transfer, not real-time temperature readings.
Kushya 2: The Rema's Contradiction on Davar Gush
The Rema’s position on Davar Gush presents a classic halakhic contradiction.
- In Hilchot Kashrut Yoreh Deah 94:7[^9] and Yoreh Deah 105:8[^10], the Rema explicitly rules like the Maharshal: a Davar Gush is treated as a Keli Rishon even in a Keli Sheni, meaning it can transfer and absorb non-kosher flavors.
- Yet, in Hilchot Shabbat Orach Chaim 318, where the Rema lists the laws of cooking in detail, he completely omits this stringency! He does not warn against placing cold items on a hot potato or meat on Shabbat.
Why would the Rema hold that a Davar Gush is a Keli Rishon for dietary laws, but ignore this status for the far more severe laws of Shabbat (which carry the penalty of Sekilah - stoning)?
┌───────────────────────────────┐
│ The Rema's Dual Treatment │
└───────────────┬───────────────┘
│
┌───────────────────────┴───────────────────────┐
▼ ▼
[ Hilchot Kashrut ] [ Hilchot Shabbat ]
- Davar Gush = Keli Rishon - Omits Davar Gush stringency
- Focus: Physical absorption (Beli'ah) - Focus: Creative labor (Melechet)
- Result: Flavor transfers - Result: Lenient in Keli Sheni
The Resolution (The Magen Avraham and Arukh HaShulchan)
This classic contradiction is resolved by a deep conceptual distinction between the physics of flavor absorption (Beli'ah) and the creative labor of cooking (Bishul Shabbat).
The Magen Avraham Orach Chaim 318:45[^11] and the Arukh HaShulchan Arukh HaShulchan, Orach Chaim 318:45 explain that the two areas of halakha operate on different conceptual planes:
- Hilchot Kashrut (Beli'ah): The laws of kosher flavor transfer are entirely dependent on physical reality (mzi'ut). If a solid food is physically hot enough to open pores and transfer flavor, then halakha must treat it as a Keli Rishon. The formal definition of the vessel is secondary to the physical transfer of fat and taste.
- Hilchot Shabbat (Bishul): The laws of Shabbat require Melechet Machshevet—purposeful, skilled, creative labor Chagigah 10b[^12]. Cooking on Shabbat is not merely about chemical changes; it is about the manner of cooking. Historically, cooking in the Mishkan was done directly on a fire (Koach Rishon). A Davar Gush sitting on a plate in a Keli Sheni may physically heat up items placed on it, but this is not the standard, creative way of cooking (derech bishul). It is an incidental thermal reaction.
Therefore, the Rema is lenient on Shabbat because the formal category of Keli Sheni removes the act from the definition of Melechet Machshevet, even though he is stringent in Kashrut because the physical flavor transfer still occurs.
Intertext
To fully appreciate how this sugya has evolved, we must trace its development from the Talmud to contemporary responsa.
1. The Talmudic Source: The Ladle (Kelech)
The Gemara in Shabbat 40b[^13] discusses the status of a ladle (kelech):
"אמר רב יוסף: האי קילוחא דכלי ראשון, הרי הוא ככלי ראשון. ולימא: כלי ראשון הוא? אלא, קילוחא דכלי ראשון ככלי שני דמי."
(Rav Yosef said: The stream from a Keli Rishon is like a Keli Rishon. But wait, why not say it IS a Keli Rishon? Rather, the stream from a Keli Rishon is like a Keli Sheni.)
The status of a ladle remains a major point of discussion in modern halakha. Does the ladle become a Keli Sheni when dipped into the pot, making the bowl into which it pours a Keli Shlishi? Or does the ladle, by sitting in the hot pot, acquire the status of a Keli Rishon itself?
[ Soup Pot (Keli Rishon) ] ──> [ Ladle (Kelech) ] ──> [ Soup Bowl ]
│ │
Is the Ladle a Keli Sheni, Making the Bowl a
or does it become a KR? Keli Shlishi?
- Rav Moshe Feinstein's View: In Igrot Moshe Igrot Moshe, Orach Chaim 4:74, Ot 4[^14], Rav Moshe rules that if a ladle is left in the Keli Rishon long enough to reach the same temperature as the soup, it becomes part of the Keli Rishon. Consequently, when you pour from the ladle into a bowl, the bowl becomes a Keli Sheni.
- However, if the ladle is dipped in and removed quickly, it does not achieve Keli Rishon status. In that case, the ladle is a Keli Sheni, and the soup bowl into which it pours becomes a Keli Shlishi—allowing for much greater leniency regarding croutons or spices.
2. Modern Application: The Tea Bag Controversy
The debate over Keli Shlishi is highly relevant to the preparation of tea on Shabbat. Tea leaves are considered the ultimate Kalei HaBishul (easily cooked items), as they are designed to release their flavor and color instantly upon contact with hot water.
┌─────────────────────────────┐
│ TEA BAG ON SHABBAT │
└──────────────┬──────────────┘
│
┌───────────────────────┴───────────────────────┐
▼ ▼
[ Stringent Opinion ] [ Lenient Opinion ]
- Chayei Adam / Mishnah Berurah - Arukh HaShulchan
- Tea is Kalei HaBishul - Keli Shlishi cannot cook
- Forbidding tea bags even in Keli Shlishi - Tea bags allowed in Keli Shlishi
- Requires pre-made "tea essence" - Color release is not Bishul here
- The Stringent View (Mishnah Berurah): The Mishnah Berurah Mishnah Berurah 318:45[^15], following the Chayei Adam, rules that because tea leaves are so easily cooked, one may not place a tea bag even into a Keli Shlishi as long as the water is yad soledet bo. This view requires the preparation of "tea essence" before Shabbat.
- The Lenient View (Arukh HaShulchan): The Arukh HaShulchan Arukh HaShulchan, Orach Chaim 318:43[^16] takes a characteristically bold and lenient stance. He argues that once water is in a Keli Shlishi, its cooking power is completely gone. The release of color and flavor in a third vessel is not Bishul, but merely the dissolution of the leaves' natural properties in warm water. He permits making tea in a Keli Shlishi without hesitation.
Psak/Practice
How does this complex thermodynamic and formalist framework translate into practical halakha today? We can boil down the practical guidelines to three main areas:
┌─────────────────────────────────────────────────────────────────────────────┐
│ PRACTICAL SHABBAT KITCHEN GUIDE │
├───────────────────┬─────────────────────────────────────────────────────────┤
│ Liquid Soup │ Soup Bowl = Keli Sheni (by ladle). │
│ │ - Yes: Croutons (if pre-baked), salt, black pepper. │
│ │ - No: Raw vegetables, uncooked spices. │
├───────────────────┼─────────────────────────────────────────────────────────┤
│ Solids (Potato/ │ Treated as Davar Gush (Keli Rishon status). │
│ Meat) │ - Yes: Cold cooked gravy. │
│ │ - No: Raw salt, butter, margarine, raw spices. │
├───────────────────┼─────────────────────────────────────────────────────────┤
│ Tea & Coffee │ Use a Keli Shlishi (Cup A -> Cup B -> Cup C). │
│ │ - Yes: Instant coffee, sugar, tea bags (per Arukh HS). │
│ │ - Note: Many still use pre-made tea essence to be safe. │
└───────────────────┴─────────────────────────────────────────────────────────┘
1. The Soup Bowl (Keli Sheni via Ladle)
- Status: If you use a ladle to transfer soup from the pot to a bowl, the bowl is considered a Keli Sheni (according to the stringent view of the ladle) or a Keli Shlishi (according to the lenient view).
- Practice: To satisfy all opinions, one should treat the soup bowl as a Keli Sheni.
- You may add pre-baked croutons (since ein bishul achar bishul—cooking does not apply to already baked items Shabbat 34b[^17]).
- You may add salt, as modern table salt is pre-cooked during processing.
- You should avoid adding raw, un-processed spices directly into a hot bowl if it is still yad soledet bo.
2. The Solid Meat or Potato (Davar Gush)
- Status: A hot, dry solid (like a baked potato or a piece of roast chicken) on your plate is treated as a Davar Gush.
- Practice: Because it retains its heat like a Keli Rishon, you must be careful:
- Do not pour cold, uncooked liquid (like raw oil or un-pasteurized vinegar) directly onto it.
- Do not melt butter or margarine on a hot baked potato if the potato is yad soledet bo (typically above 43°C or 110°F).
- You may pour warm gravy that was already cooked before Shabbat onto the meat.
3. Making Tea and Coffee
- Instant Coffee: Since instant coffee is fully cooked and dehydrated during manufacturing, you can pour hot water from a Keli Sheni (or even directly from a hot water urn, which is a Keli Rishon, though some prefer iruy from a Keli Rishon) onto it, as ein bishul achar bishul applies to dry foods.
- Tea Bags:
- To follow the Mishnah Berurah, one should prepare a liquid tea essence before Shabbat and simply add this concentrated liquid to hot water.
- To follow the Arukh HaShulchan, you may pour hot water from your urn into Cup A (Keli Sheni), pour that water into Cup B (Keli Shlishi), and then place the tea bag directly into Cup B.
Takeaway
The laws of Shabbat cooking balance physical reality with formal halakhic categories. Just as the dense Davar Gush preserves its heat in a cold vessel, our commitment to halakha preserves our warmth and identity in a changing world.
Footnotes
[^1]: Arukh HaShulchan, Orach Chaim 318:41 [^2]: Arukh HaShulchan, Orach Chaim 318:44 [^3]: Tosafot, Shabbat 40b, s.v. "U'shma mina" [^4]: Yam Shel Shlomo, Pesachim 2:25 [^5]: Chidushei HaRashba, Shabbat 40b, s.v. "Ha d'Amrinan" [^6]: Siftei Kohen (Shach), Yoreh Deah 105:8 [^7]: Arukh HaShulchan, Orach Chaim 318:43 [^8]: Pri Megadim, Eshel Avraham, Orach Chaim 318:41 [^9]: Rema, Yoreh Deah 94:7 [^10]: Rema, Yoreh Deah 105:8 [^11]: Magen Avraham, Orach Chaim 318:45 [^12]: Chagigah 10b [^13]: Shabbat 40b [^14]: Igrot Moshe, Orach Chaim 4:74, Ot 4 [^15]: Mishnah Berurah 318:45 [^16]: Arukh HaShulchan, Orach Chaim 318:43 [^17]: Shabbat 34b
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