Daf ha-kashrus

Bishul on Shabbos Part I: Table Salt

Can a person, on shabbos, add table salt to a kli rishon off the fire, even if there are additives in the salt?

Before answering the question about the additives, it is important to clarify whether salt itself, even if there are no additives, can be added to a kli rishon off the fire.

The Gemara (Shabbos, 42b) cites two opinions about cooking salt on Shabbos. Although generally no uncooked food can be added to a kli rishon – even when removed from the fire – salt, according to one opinion, is different. The quality of salt is such that it won’t truly be cooked unless it is added to a pot that is actually on the fire. Therefore, the prohibition applies only in that case; it is, however, permitted to add salt to a pot provided it has been removed from the fire. The second opinion holds that salt is fairly easily cooked, and therefore it should not be added even to a kli sheini.

Shulchan Aruch (OC 318:9) rules according to the lenient position. About someone who conducts himself according to the strict opinion the Rema writes: תבא עליו ברכה.

Mishnah Berurah (318:71) notes that if the salt had been cooked during its production process, then even the stringent position
would agree that it may be placed in a kli rishon (removed from the fire), based on the principle of אין בישול אחר בישול.

What about contemporary processing methods? Is there a production stage in which the salt is cooked?

Salt processors employ a number of methods for recovering salt, depending on variations in geographic and economic resources. These include:
–  Mining, a process that does not require heat
– Solar Evaporation, which also does not require heat (other than the sun)
– Solution mining, which does require heat, but only selectively
– Mechanical compression (the heat generated is not a תולדות האש)

In each of these cases the salt must undergo a final drying step to remove residual water such that the moisture level of the final product is below 0.1%. Salt is dried in an oven, and heated to about 200-300˚ F, for about ten minutes.

The OU poskim have ruled that although the primary processing stages, identified above, do not guarantee that any given sample of table salt has been cooked, the drying stage can be considered an אפיה, and we can be lenient according to the position of אין בישול אחר אפיה (Shulchan Aruch, 318,5). Although we generally adopt the position of יש בישול אחר אפיה , we do so only when the question involves a safek d’oraisah. However, since the question of placing salt into a kli rishon off the fire is no more than a chumrah, we can follow the lenient position of אין בישול אחר אפיה. When salt is mined – the first process described above — the salt does not undergo a drying step. See OU Document S-12 for an elaboration of these halachos.

What about the additives? Table salt can contain anti-caking agents and iodide. These additives are mixed into salt at less than .005 percent (or 50 parts per million). If the additives were cooked, the problem would resolve itself, as discussed above. But this is not necessarily the case (see table). Will the additives create a concern of bishul on Shabbos, or can we consider them בטל in the salt?

Rav Shlomo Kluger (Sefer HaChaim, 318, 9) discusses a similar question. May one add uncooked salt to a pot on Shabbos,, in a situation where the salt will be בטל? Although he suggests a מלהך to be lenient, he concludes that unlike ביטול of מאכלת אסורות, the concept of ביטול cannot be applied to בישול בשבת. Therefore, if an ingredient in a food is not cooked, the food must be considered raw even if regarding מאכלת אסורות we would consider that ingredient to be batul.

Though Rav Schachter, shlita, was not convinced that bitul does not apply, he pointed out that even if it was an issue, in this context it certainly would not be a concern. This is because, with the exception of dextrose and sugar, which are in any event cooked during their preparation, the other additives are all non-food items. The restriction on bishul on non-food items is very different than for foods. The criterion for cooking a non-food item is that the physical properties of the material change from one state to another; soft, wet wood, for example, must become dried and stiffened, or metal softened (Mishnah Berurah, 318, 1). Since adding salt to a pot of food will not change the physical properties of these additives, there is no concern of bishul on Shabbos.

Rav Belsky, shlita, added that these additives are so far below the radar screen in terms of כוונת בישול that even Rav Shlomo Kluger could agree that bitul would apply. In the case Rav Shlomo Kluger was discussing, though the salt was batul, there was clear intent to cook the salt. While in our case, the additives have no importance at all, and as such all should agree that they are batul.

Any table salt can therefore be added to a kli rishon (off the fire) on Shabbos, according to all opinions.

by Rabbi Gavriel Price, RC, Ingredient Registry

The Halachic content of this article was edited by Rabbi Eli Gersten, RC Recorder of OU Psak and Policy

Thanks to Glen Nishimura, Manager of Regulatory Affairs, Morton Salt, and Dr. Bonnie (Gersten) Piekarz, Materials Science and Engineering Division, US Department of Energy, for assistance.