Question: I prepared fish and meatballs before Shabbat. Before Shabbat, I tasted both the fish and the meatballs (which had since cooled off) and I added salt to the fish and black pepper and cumin to the meatballs. I was told that it will now be forbidden for me to warm up these dishes on the electric hotplate on Shabbat since the salt and spices were never cooked yet. Is this correct?
Answer: We have discussed several times that when food is being cooked in a pot, as long as the pot is hot, anything placed into it will be cooked as well, even when the pot is taken off the fire. For instance, if one cooked soup in a pot and took the pot off the fire and one now wishes to put some parsley leaves in the soup, this is forbidden due to the prohibition of cooking on Shabbat since the parsley will be cooked in the pot although it is no longer on the fire.
It is for this reason that Maran Ha’Shulchan Aruch (Chapter 318, Section 9) rules that it is forbidden to add spices to a boiling pot of food on Shabbat since it is forbidden to cook the spices on Shabbat.
The reason we permit heating up foods on Shabbat, such as fish or meatballs (obviously with only a minimal amount of gravy or sauce), is because these dishes were already fully-cooked before Shabbat and only warming is being done on Shabbat, not cooking.
Let us now address the question at hand. In the above scenario, spices were added to the dishes before Shabbat when the food was no longer hot. Thus, the spices added to the dishes were not cooked at all and by placing these pots onto the electric hotplate on Shabbat, the spices will immediately begin to cook which constitutes a prohibition of cooking on Shabbat.
Therefore, one who adds spices to a pot of food before Shabbat and the spices were not sufficiently cooked before Shabbat, the pot of food may not be heated up on Shabbat. In the above scenario, it would have been forbidden to heat up the meatballs on Shabbat.
Regarding the fish which had salt added to it before Shabbat, although all opinions agree that it is forbidden to cook salt on an electric hotplate on Shabbat, nevertheless, salt nowadays which is extracted from sea water is actually cooked in the factory where it is produced, i.e. after it is dried, it is boiled to remove the remaining moisture still contained in it. Indeed, Hagaon Yalkut Yosef Shlit”a writes that salt nowadays has already been cooked (at least according to the Sephardic custom) and may be reheated on Shabbat on an electric hotplate. Thus, a dish which had salt added to it before Shabbat may be reheated on Shabbat on an electric hotplate and this does not constitute a prohibition of cooking on Shabbat. However, special salt (such as Himalayan salt which is commonly sold in a pink color and is extracted from the depths of the earth) which has never been cooked may not be reheated on Shabbat.