Drinking Cheekful for Shabbat Kiddush

As on Jewish festivals, the minimum total volume of Shabbat kiddush beverage that must be drunk--usually by the kiddush-maker (mevareich) but it may even be by several people combined--is a cheekful (m'lo lugmov), as follows:
  • 2 fl. oz. (59 ml) within 30 seconds of beginning to drink for d'oraita cases such as Shabbat evening kiddush (as well as first-night Jewish festival kiddush and all havdalas), and
  • 1.7 fl. oz. (50 ml) within 30 seconds of beginning to drink for d'rabanan cases such as Shabbat lunch kiddush (as well as first-day Jewish festival lunch kiddush and all second-day Jewish festival kiddushes).
Note If no one drinks the kiddush beverage, a blessing was made in vain (bracha l'vatala), and the commandment to say or hear kiddush has not been fulfilled.