How much must one drink at Havdalah?

Hi,

How much must one drink for havdalah?

The cup used for havdalah should contain at least a reviit (3.3 fluid ounces, per Rav Moshe Feinstein, viewing this as a rabbinic mitzvah for which one may be lenient regarding the drinking threshold). The person reciting havdalah should drink at least this amount, ideally, to avoid doubt regarding the need for a berachah after drinking. The minimum amount is a cheekful, which is half of a reviit.

The person reciting havdalah may give the cup to another person who will drink a cheekful; this may be a child who is mature enough to be educated in the mitzvah of havdalah. In a case of need, multiple people may combine to drink that amount. The listeners may not speak until after someone has consumed a cheekful.

Should no one consume a cheekful, the listeners would not recite havdalah again, and could consider their obligation fulfilled. However, they should try to hear havdalah recited by someone else, if possible.

(Pesachim 107a; Shulchan Aruch Orach Chaim 271:14; Shulchan Aruch haRav Orach Chaim 190:4; Kaf haChaim 296:16; Mishneh Berurah 296:6, 296:9; Aruch haShulchan Orach Chaim 296:15; Igrot Moshe Orach Chaim 4:70:1; Teshuvos v'Hanhagos 1:257; Shemirat Shabbat k'Hilchatah 60:36-37, footnote 139)

Have a great day,
Mordechai