Q. There are different food scent additives available in stores, that enhance the smell of dishes and are highly recommended for people with diet limitations such as salt or sugar, as they compensate for their shortage. Is it permitted to add those scent additives to food in Shabbat or is it molid?
A. Our Torah recognizes in many ways the importance of smell and fragrance, as with reciting correct brochos, in korbonos such as ketores, or in smelling prohibited smells.
We are aware that if you pinch your nostrils when you eat, you’ll rarely taste anything. That fact is why food scientists use chemical aromatics, essential oils, and botanical extracts to enhance the flavor of food and beverages. the use of aromas to compensate for the loss of taste in low-salt or low sugar food.
Poskim disagree if there is a prohibition of molid when adding aromatic agents to food.
Shulchan Aruch (O.H. 511: 4) rules that it is prohibited in Yom Tov to burn mugmar or to scatter various spices over coals and create incense for perfuming a house or utensils, however, it is permitted to do so for sweetening fruits. Eliahu Rabba (128: 8), Chacham Tzvi (92), Shaar Hatzion (511: 18), Aruch Hashulchan (511: 12), Shemiras Shabbos K. (11: 39) and others rule that there is no molid prohibition at all on imparting scent to foods, as we add all kinds of spices to them. Others disagree (See Piskei Teshuvos 322: n. 67).
Horav Shlomo Miller’s Shlit’a opinion is that one can be lenient.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a