[In these short halachic articles we will try to examine interesting halachic questions, and understand both sides of the issue at hand… or on the other hand.]
Rav Da’vid Sperling.
How Much Wine Do We Need To Drink At Seder?
The four cups at the seder are famous – one for each verse of redemption, ho’tzaiti, hi’tzalti, ga’alti and lakachti. The cup itself has to hold at least a revi’it (86-150ml according to the different opinions), and be filled to the top with wine – but how much of the cup do we need to drink each time?
The Gemara (Peshachim 108b) states “Said R. Nahman b. Isaac: [One fulfills their obligation of drinking] providing that they drank the greater part of [each] cup”. What does the majority of each cup mean? The simple reading, which is followed by the Ramban, is that one has to drink more than half the glass no matter how big the glass is. If you have a mug that holds a pint, you must drink more than half a pint!
On the other hand, Tosafot explains that while one should ideally drink a full revi’it, Rav Nahman comes to teach us that it is enough to drink the majority of a “cup”, that is a classic halachic cup which holds a revi’it.
This argument is probably dependent on the status of the four cups. Tosafot believes that wine comes to accompany the mitzvot of the seder – Kiddush, Maggid (telling the story), Bentching, and Hallel. This is just like the glass of wine we use to mark other important mitzvot, like a wedding, brit or havdallah. Because the important thing is the mitzvah, and the wine is just an accompaniment to give the mitzvah importance, it is enough to taste from the cup – and a minimal taste is a cheek-full, or slightly more than half a revi’it.
On the other hand, (as the Bach 472 explains), the Ramban would argue that the four cups are the mitzvah in and of themselves, in order to show our freedom. Therefore, one needs to drink the full cup itself, not just to taste some wine. If one is unable to drink the whole cup, Rav Nahman comes to tell us that the majority of the cup is considered as if one had drunk a cup of freedom.
This explanation fits in with another argument between Tosafot and the other Rishonim. The Tosafot (Pesachim 99b) raises the possibility that just like with the Shabbat Kiddush it is enough (from the letter of the law) for one person to make kiddush and drink in order to exempt all those present, so too with the four cups. This would be because he believes the cups are just an accompaniment to other mitzvot of the seder, as we said above. On the other hand, the other Rishonim (and the halacha) stress that every person must individually drink. This is in line with the logic of the Ramban that the mitzvah is to drink four cups of wine, signifying liberation and freedom.
The Shulchan Aruch, Orach Haim, 472,9, rules that the halacha is like Tosafot, but brings the Ramban as a second opinion. The Mishna Brurah (ibid 33) advises someone who is unable to drink the whole, or majority of their large glass (as per the Ramban) to make sure they use a smaller cup that only holds one revi’it. If a smaller cup of one revi’it is used, then according to all opinions one fulfills their mitzvah by drinking at least half of it.