Rabbi Mendel Agranovich
Shalom, dear readers!
We continue the discussion of the prohibition against cooking on Shabbat that we began in the previous issue. Let us examine this question step by step.
First, as we should, let us turn to the source and ask: if all the prohibitions stem from the construction of the Mishkan (the portable Temple), then where did they cook, and what did they cook there?
We find the answer in tractate Shabbat (74b). It states that dyes were cooked from seeds to color the fabrics that covered the Mishkan.
In chapter 9 of the laws of Shabbat in the Rambam’s code, “Mishneh Torah,” it is written:
“Whether one cooks food, heats water, or bakes bread, it is all one and the same.”
The prohibition against cooking applies not only to food or water, but also to all other materials that change their properties and physical characteristics as a result of being heated. For example, the same passage states that melting metal, resin, or wax is a derivative of this prohibition. Why a derivative, you may reasonably ask? The reason is that these changes do not last: as the materials cool, they return to their original state, and it would seem that no result of the cooking remains. But since the melting process itself is clearly a form of heat treatment, it obviously falls under the definition we have given.
But what kind of thermal energy is meant? After all, heat can come from fire, electricity, the sun, or the decomposition of a substance, and it can be the result of a chemical reaction.
The Talmud (Shabbat, 39a) states that it is permitted to cook using the sun, but this applies to heat coming from the sun itself. Objects heated by solar energy may not be used. Let us explain. Cooking with solar energy is entirely different (as an action) from cooking over a fire; it is not a customary human practice and, consequently, clearly differs from what the Torah prohibited. Briefly put, no one cooks this way (disregarding the exceptions, which only prove the rule).
That is, most cooking throughout the world takes place over a fire or using objects heated by it to such a degree that a substance cooks on contact with them. For example: on a sheet of red-hot metal or in a vessel containing hot water.
But what about cooking with heat derived from the sun? Here it is quite simple: looking at a material, it is impossible to determine how it was heated. Our Sages therefore decreed that no sources of derived heat may be used, since this could lead to using heat derived from fire.
An interesting interpretation of this law was proposed by the author of “Eglei Tal.” In his opinion, the result of cooking in the sun differs from the result of cooking over a fire. We can only add that the difference is very substantial. What is that difference?
Rabbi Moshe Feinstein writes in his book “Igrot Moshe” that using a microwave oven on Shabbat nowadays is prohibited by the Torah, because electromagnetic waves are the same energy as that of the sun, with just one difference: nowadays, people cook this way! But we have already noted that the reason for permitting it is simply that people do not cook this way; without this rationale, the ruling becomes the exact opposite.
But if we follow the opinion of the Sochatchov Rebbe (the author of “Eglei Tal”), cooking with electromagnetic waves does not produce the same result! And it makes no difference what is customary nowadays! Incidentally, my personal experience shows that food prepared in a microwave tastes quite different, but that is an insufficient experimental basis, as physicists say. It therefore follows that someone who heats cold water in a microwave violates the prohibition against using electricity, but certainly not the prohibition against cooking. And if a microwave is programmed to open at a particular time, something is placed inside it, and it then closes, switches on, and opens on its own, it could be used, for example, for someone who is ill. Bold, but logical!
Let us note that Rabbi Feinstein's opinion is accepted as the primary position, while the Sochatchov Rebbe's opinion requires further proof. It therefore cannot be relied upon without consulting a competent rabbi.
What about cooking on an electric hot plate? As we have already noted, the Torah prohibits cooking over a fire or with heat derived from it. Red-hot metal is the same thing; covering a heating coil with something for safety does not change its essential nature, so the answer is clear.
(An amusing anecdote is told on this subject. There are two popular lecturers here in Israel who spread Torah among the general public. One advocates a scientific approach to the subject, while the other is known for being able to get through to any Jew. Both were asked: are an electric hot plate and fire the same thing or not? The first began explaining “You see, from the perspective of Torah and physics, and so on and so forth.” The second simply asked: “It isn't fire? Then sit on it!” Gets the point across, doesn't it?
But jokes aside—let us continue with our serious work.
Let us draw a practical conclusion:
1) Food may be cooked using direct sunlight (this occasionally occurs; an example from the Talmud: a pot of cold water is placed in the sun to heat up).
2) One may not cook on any surface (a black one, for example) heated by the sun (cracking an egg onto a handkerchief to fry it, or burying it in sand or road dust to cook it).
3) An electric kettle, water heater, oven, glass-ceramic cooktop—none of these may be used for cooking on Shabbat. For example, the egg mentioned above may not even be placed beside them—in a spot where it could cook.
4) The use of “dud shemesh”—domestic water heaters powered by solar energy—is a subject that requires a separate article, as well as the introduction of several additional concepts.
5) Using heat released during decomposition or a chemical reaction is prohibited by the aforementioned decree of the Sages.
See you in the next issue!