We will start with the background and the standard instructions for eating after making or hearing Kiddush and then see some points of possible leniency. Although the basic principles are much the same for Kiddush at night and in the daytime, the poskim and common practice are more lenient regarding the daytime Kiddush (Kiddusha Rabba). This is because that Kiddush is a rabbinic obligation, whereas the nighttime Kiddush is a biblical obligation.[1] Therefore, not all of the leniencies we entertain regarding Kiddusha Rabba can be applied to Kiddush at night.
The gemara[2] records the opinion of several Amora’im that Kiddush needs to be made at the place of a meal, and the Shulchan Aruch[3] concurs. The source for this requirement is the pasuk in Yeshaya (58:13): “and you shall call Shabbat a delight,” from which we derive that the proclamation of the day of Shabbat (Kiddush) should be connected to partaking in delights (a meal). [4] Yet, in describing an actual case, the gemara talks about tasting something after Kiddush, from which the poskim understood that a full meal is not necessary to validate the Kiddush. However, the question remains: how much is needed, and of what foods?
The Shulchan Aruch[5] cites the Geonim as follows: “Even if he ate a little bit or drank a cup of wine for which he is required to make a beracha, he fulfilled [the obligation of] Kiddush… but only if he ate bread or drank wine; however, if he ate fruit, no.” The Acharonim[6] reason that the requisite quantity for a beracha must refer to the beracha after eating (beracha acharona), since a beracha before eating is required for any amount of food. The minimum amount one needs to eat is, therefore, a k’zayit[7] of solid food or a revi’it[8] of wine. (There are opinions that a revi’it is not necessary and others that it is not sufficient to be considered the place of a meal.[9]) We advise avoiding the use of wine or grape juice to fulfill the meal requirement at public Kiddushes because often there is not enough wine for many people to drink so much. Of course, derech eretz is an important concern from any healthy Jewish perspective.
The Magen Avraham[10] uses the Geonim’s logic to expand the list of foods that fulfill the purpose at hand. This includes some foods made from the five major species of grain, which are more meal-like than wine, as we find in the context of the requirements of seuda shlishit. Most Acharonim assume that such foods need not be pat haba’a b’kisnin (cake and the like, which have some bread-like qualities and halachic status). Rather, any food that obligates one to make a beracha acharona of Al HaMichya suffices.[11]
The preceding are the standard recommendations for meeting the halachic requirements of Kiddush. However, we want to mention some less standard, yet legitimate, lenient positions. The Chayei Adam[12] says that if one is somewhat weak and does not have any grain-based food available, he may rely on the opinion that even fruit (or, apparently, any food) is sufficient to satisfy the meal requirement of Kiddush. The Sha’arei Teshuva[13] says that when one makes Kiddush for a group, every person who wants to make use of the Kiddush to eat and/or to fulfill the mitzva must himself eat the requisite amount of the correct foods. However, B’tzel HaChochma[14] cites a minority view that it is sufficient for one person from a group which took part in a given Kiddush (by reciting or listening) to eat. According to this approach, once someone connects the Kiddush to a meal, others can rely on that Kiddush without connecting it to their own meal. Knowledge of these opinions will help restrain one from correcting others (which should generally be avoided when not absolutely necessary) and can be used in extenuating circumstances. Several poskim indicate that the circumstances need not be dire in order to apply reasonable leniency in this matter, which, while we do not treat it lightly, is not a particularly strict area of halacha. Such situations include (but are not limited to) cases where there is not enough cake for all and when a person has health concerns about eating carbohydrates at that time.