This week we read Parshat Hachodesh. Both the maftir and haftarah detail halachot related to the upcoming yom tov of Pesach. As such, it would appear to be an opportune time to review a halachic debate that is of particular significance to contemporary observance of this festival.

R. Moshe Feinstein famously ruled that the four cups of wine at the seder ("arba kosot") must contain alcohol, and that consequently one cannot use grape juice to fulfil this obligation.

R. Moshe is quoted by his son, R. David Feinstein, in his Kol Dodi hagaddah, as having cited the gemara in Pesachim (108b) as proof for his position. The gemara there states that someone who drinks wine that has not been diluted (wine was typically diluted in Chazal's times, with only one part wine for every three parts of water) for the arba kosot fulfills the mitzvah of drinking wine, but not the obligation to celebrate freedom (“cheirut”). The Rashbam explains that using undiluted wine does not fulfill the Mitzva of arba kosot fully, because “only diluted wine is prestigious (chashuv).” R. Moshe contends that the application of the principle of ‘chashivut - prestige’ in our times demands that only wine (containing alcohol), and not grape juice (lacking alcohol), can be used. A drink without alcohol is not prestigious, and on the basis of this gemara as explained by Rashbam, is therefore insufficient for the mitzvah.

R. Moshe brought another proof to his position from the Talmud Yerushalmi (Pesachim Chapter 10). The Yerushalmi says that after drinking the arba kosot at the seder, Rav Yona had a headache until Shavuot. R. Moshe argues that if Rav Yona would have deemed grape juice acceptable for arba kosot, then he would surely have preferred it to wine, given wine's side effects. We can infer from here that using grape juice was not a halachic option for Rav Yonah, and that is why he drank the wine and endured its consequences.

However, in a recently published responsum (Teshuvot Minchat Asher 3:37), R. Asher Weiss takes issue with R. Moshe's position and argues that grape juice is indeed acceptable for the mitzvah of arba kosot.

R. Weiss cites the Shulchan Aruch Harav (472:27) who writes explicitly that "all wines that are permitted for kiddush on shabbat and yom tov may be used for the arba kosot". Inasmuch as grape juice is valid for kiddush, as per the Gemara in Bava Batra (97b) which states that a person may "squeeze grapes and recite kiddush on the juice", then it should be valid for arba kosot too.

R. Weiss provides support for this claim when he notes that, whereas in hilchot kiddush, the Shulchan Aruch goes into great detail discussing the validity (or otherwise) of various types of wine for kiddush, there is no such discussion in hilchot pesach. The inference is that any type of wine/grape juice is allowed.

R. Weiss also draws a somewhat difference from the first gemara cited above. He notes that, insofar as Chazal did not consider drinking undiluted wine "derech cherut", it is clear that excess alcoholic content (to the extent that the wine is unpleasant to drink) is in fact a hindrance to proper fulfilment of the mitzvah. Further, the Piskei Rid writes that drinking undiluted wine is "derech shikrut" (drunkenness) and not derech cherut. As such, it is hard to argue that alcohol itself is what generates the "derech cherut" in the first place when it seems that alcohol, or at least excess alcohol, is undesirable.

R. Moshe's proof from the story of R. Yona’s headache in the Talmud Yerushalmi is predicated on the assumption that he had access to grape juice. In fact, as the Gemara in Brachot (35b) notes, the harvest season for grapes is in Tishrei. Until recently, grape juice could not be preserved for months afterwards, so by Pesach time there was simply none available. Therefore, Rav Yona could not drink grape juice not because it was halachically unavailable, but simply because it was practically unavailable. Accordingly, no inference can be drawn from this gemara as to the permissibility of grape juice.

It should also be noted that, contrary to common perception, wine in the time of Chazal was in all likelihood no stronger than wine nowadays. Wine naturally ferments to a maximum of about 14% alcohol - and the alcoholic content of wine in Chazal's times was likely slightly lower than this due to evaporation. Yet even so, as we have seen, it was common to dilute wine with three parts water to one part wine. This would mean that the alcoholic content of the wine actually being drunk (and optimally so for the arba Kosot) was in the region of 3-3.5%. Based on this reasoning, R. Yisrael Belsky z"l (posek for the OU) ruled that even those who seek to fulfil the opinions that require the arba kosot to contain alcohol (along the lines of R. Moshe Feinstein) may dilute wine with grape juice to this level.