We are skipping siman 27, which discusses a person who does not have wine, bread or fruits for kiddush. Baruch Hashem, we do not have this challenge.
In siman 28, the Chayei Adam writes that the Gemara discusses making kiddush in shul. People traveling would often sleep and eat in the shul over Shabbos (or, as Tosfos clarifies, in a side room). Therefore, Chazal instituted that the shuls should make kiddush at the end of davening to help the travelers fulfill their obligation.
The Chayei Adam writes that nowadays, where we do not have this reality of travelers sleeping in the shul, the minhag is to continue to make kiddush in the shul or beis medrash. To be clear, it is a machlokes whether we still maintain this minhag or not, but the Chayei Adam is of the opinion that it is still performed. The Chayei Adam also adds that kiddush is performed in a beis medrash, even though the Gemara does not mention beis medrash at all. Some who maintain the minhag should still be performed argue with the Chayei Adam regarding performing kiddush in a beis medrash, and hold that Chazal never instituted the minhag in a beis medrash.
We have learned that kiddush must be b’mokom seudah, in conjunction with a meal. In shul, it would appear that there is no meal, and, if so, the person making kiddush cannot eat or drink, meaning they cannot even drink the kiddush wine even though they made a bracha. The Chayei Adam writes that the wine should be given to a child. We need to define the age of this child. If the child is above the age of chinuch, the child has an issur to eat without a makom seduah as well. If so, the child must be under the age of chinuch.
The Magen Avraham disagrees, and writes that we find many times that Chazal do not impose issurim regarding food and eating for a koton. Intrinsic food issurim (e.g., non-kosher food) apply to a koton once they have reached the age of chinuch, but secondary issurim, such as those related to timing, are not applied to a koton. Chazal were concerned for a child’s health and need to eat, and therefore did not extend those types of issurim to them. The accepted minhag is to follow the Magen Avraham.
If there is no child, the person who makes kiddush should drink a revi’is, in order to be yotzei kiddush b’mokom seudah through wine. The Chayei Adam specifically states he only needs to drink a revi’is, and not a revi’is plus a melo lugmav. We see from here the opinion of the Chayei Adam that one does not to drink a revi’is in addition to the melo lugmav, but a revi’is is sufficient. We learned that multiple poskim disagree with the Chayei Adam, and it is appropriate to drink both the revi’is and melo lugmav.
Practically, we calculated a revi’is as 3 oz for these purposes, so a melo lugmav is 1.5 oz, for a total of 4.5 ounces.
Summary
- The Chayei Adam writes the minhag is to make kiddush on Friday Night in shuls and batei medrash. The wine should be given to a koton, and if there is no koton, the person making kiddush should drink a revi’is plus melo lugmav.
