Which Foods are Forbidden on Yom Kippur?

  • Rav Moshe Taragin
In a previous shiur, we discussed the possible distinction between the classic prohibition to eat forbidden foods and the issur to eat or drink on Yom Kippur. Is the prohibition on Yom Kippur defined in classic terms of eating, perhaps with the added stipulation that the eating be satisfying? Or is the prohibition on Yom Kippur completely unrelated to any formal act of eating, consisting purely of the disruption of inuy? That shiur probed the mechanics of akhila and whether the standard criteria for eating applies to Yom Kippur. In this shiur, we will explore a related issue – the question of which items are included in the prohibition.
The gemara (Yoma 80b) claims that liquids that flavor solid food or leftover water from cleansing vegetables can contribute to the shiur of kotevet on Yom Kippur.  Even if the actual vegetable is less than a kotevet, the saltwater that lies on its surface after immersion can complete the necessary shiur. The Tosafot Yeshanim raise an interesting question, noting that these ancillary liquids are usually considered liquid and not subcomponents of the vegetable/solid (in the context of the laws of netilat yadayim). Why, then, should they contribute to the shiur of the solid vegetable on Yom Kippur? The answer of the Tosafot Yeshanim is quite revealing: Since the prohibition on Yom Kippur is not defined by eating, the differences between solids and associated liquids are blurred, as they both contribute to one combined disruption of inuy.
This specific situation of solids and their ancillary liquids echoes a more general machloket regarding the combinative potential of unrelated solids and liquids. Indeed, naturally-associated liquids, such as salad dressing, may contribute to the experience of eating a salad, thereby creating an integrated break of the necessary inuy on Yom Kippur. But do unrelated liquids and solids create that effect? If one drinks a bit of liquid and eats a bit of food, does he violate the command of inuy?
The question arises within the position cited in the mishna (73b) that unrelated liquids and solids cannot combine to produce the shiur for Yom Kippur prohibition. R. Chisda believes that this is the minority opinion of R. Yehoshua, whereas the Rabbanan would allow combinations of liquids and solids. By contrast, R. Nachman views the inability to combine unrelated solids and liquids on Yom Kippur as the general consensus. Even if under normal circumstances we can envision a possible combination, that option does not apply on Yom Kippur. Evidently since unrelated solids and liquids do not produce a joint sensation of satiation, they cannot be combined for a “shiur” even according to the Rabanan who typically allow these combinations (80b).
A final example of foodstuffs whose status on Yom Kippur may be affected by the nature of the prohibition pertains to the condition of akhila gasa. The gemara claims that sever overeating does not violate the issur of eating on Yom Kippur. If a person ate plentifully on Erev Yom Kippur and ate in a gluttonous fashion during Yom Kippur itself, he would not violate the prohibition. In the context of the korban Pesach, gluttonous eating is considered halakhic eating, and it should consequently be forbidden on Yom Kippur. Perhaps this exemption is also reflective of the unique nature of the Yom Kippur prohibition. Since this type of eating provides no enjoyment (and the gemara even refers to it as mazik, destructive), it cannot be forbidden on Yom Kippur, even though it typically classifies as an act of eating.