22. Eirusin. Birkas Eirusin, i.e., the bracha the mesader kiddushin makes under the chuppah—“אשר קדשנו במצותיו וצוונו על העריות וכו'”—requires a kos. The bracha of Borei Pri HaGafen is said before Birkas Eirusin. Although it is not a chiyuv, and if there is no wine or other drink classified as chamar medina available, Birkas Eirusin is said without a kos, when wine is available we make the bracha with a kos (שו''ע אבהע''ז סי' ל''ד ס''ב ).
23. Nisuin. A kos is required for Birkas Nisuin, i.e., the seven brachos said under the chuppah. Borei Pri HaGafen is made first, followed by six brachos. Some Rishonim hold the kos is not absolutely essential [not מעכב ] (רמב''ם פ''י אישות, רוקח סי' שנ''ב ); others hold it is (רא''ש ריש כתובות ).
24. Sheva brachos. We say sheva brachos—first six brachos, then Borei Pri HaGafen—following Birkas HaMazon after a seuda held in honor of a chosson and kallah if there are ten men and a “panim chadashos” present. Some hold that the machlokes Rishonim whether a kos is essential applies here too (ספר בית שער ס''ב ס''ו, שו''ת משיב הלכה ח''א סי' של''ו ); others hold all poskim agree a kos is required (שו''ת התעוררות תשובה ח''ב סי' ק''ג ); yet others hold all poskim agree a kos is not essential (אבן פינה דרישת הארי סק''א ).
