515. Kiddush in Shul
76:7 The bracha mei’ein sheva, the bracha that corresponds to the seven brachos of the Shabbos Amidah, is only said with a regularly-established minyan, but not with a “pick-up” minyan, such as occurs at the home of a sheva brachos or a mourner. If a place is designated for a Shabbos minyan for a number of weeks, it should be said. (It may be said when davening in a person’s home where a minyan forms regularly for a number of days so long as there is a Torah scroll present - Mishnah Brurah 268:24.)
76:8 Nowadays, it is customary for the shaliach tzibbur to recite Kiddush in shul on Shabbos and yom tov evenings, other than the first two nights of Pesach. Since he does not fulfill his own obligation in Kiddush through this, and since one may not eat or drink anything before fulfilling Kiddush, the wine should be given to a child who has reached the age of education (6 or 7 – MB 269:1) so that the bracha not be recited in vain. The child, of course, should listen to the bracha being recited. If no child is present in shul, the one saying Kiddush, or another adult, should intend to fulfill his obligation with this Kiddush and drink a revi'is (3.3 ounces), after which he should recite the concluding bracha of al hagefen. Nevertheless, the one who drank may still make Kiddush in his home for his wife and the members of his household if they need him to. One may be covered by the Kiddush in shul even though Kiddush must normally be recited at the place where one will have his meal. When necessary, we rely the authorities who consider it sufficient that one drink a revi’is. It is preferable to drink a revi'is in addition to the mouthful of wine so that the mouthful was for Kiddush and the revi'is is in lieu of a meal. (This opinion should really only be relied upon in a case of absolute necessity – MB 273:25.)