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By Rabbi Dovid Cohen, Administrative Rabbinic Coordinator
Q. Is it okay to make instant coffee, tea, or hot cocoa on Shabbos?
A. It is forbidden to cook on Shabbos; one of the rules of bishul/cooking is that ain bishul achar bishul, which literally means that once something is fully cooked it is (halachically) impossible to cook it again. In practice this means that there is no violation of bishul on Shabbos if you cook food that is already cooked.
There are two relevant details of this halacha. Firstly, the halacha differentiates between bishul, which refers to cooking in water or frying in oil, and afiyah, which refers to baking or broiling with plain heat and no liquid. Thus, there is no bishul after bishul, and there is no afiyah after afiyah, but there is bishul after afiyah or vice versa. Secondly, there is a difference between solids and liquids. Once a solid food is considered “cooked”, it never loses that status. However, a liquid is only considered “cooked” as long as it is still somewhat hot or warm; once it cools completely the cooking is considered undone, and if someone heats it up that is a violation of bishul.
Let us now apply these principles to the questions at hand. The “instant” versions of coffee and tea are cooked in water at the factory, and the water is removed (often through an additional “cooking”) to convert it to a powder. [Ground coffee and tea bags are not cooked and should not be used on Shabbos.] Thus, the instant coffee and tea have been cooked, and since ain bishul achar bishul, it should be permitted to put them into hot water on Shabbos. However, some are machmir on this, because the coffee and tea powder dissolve into the water and should, therefore, be viewed as a liquid (rather than a solid), where bishul can happen if the original item is no longer hot. Most disagree with this and say that the powder is viewed as a solid where ain bishul achar bishul applies, even if it has cooled completely. Minchas Yitzchok 1:55 suggests being concerned for the strict opinion and, therefore, advises that the coffee or tea powder be put into a cup of hot water (kli sheini) rather than pour the hot water from the urn onto the powder (irui kli rishon). See also Iggeros Moshe OC 4:74 (#16 in the Bishul section).
The above is relevant when the only ingredient is instant coffee or instant tea. But sometimes companies will add raw ground (“micro-ground”) coffee, flavors, sweeteners, or other ingredients to the powder. In that case, whether one may use instant coffee or tea depends on whether those ingredients were cooked at the factory. This concern is even more prevalent for hot cocoa mixes: the cocoa powder per se is cooked as part of its processing, but there are commonly many other ingredients, and each one must be evaluated to determine if the overall powder can be heated/made on Shabbos.
This article first appeared in the Let’s Talk Kashrus column, Yated Ne’eman, October 27, 2023.