When a couple gets married, just before the Kiddushin, the officiating Rabbi (Mesader Kiddushin) recites a Beracha called Birkat Erusin, which is preceded by the Beracha over wine – Boreh Peri Ha’gefen. After he recites these Berachot, he gives the cup to the bride and groom and they both take a sip of the wine. (There is no minimum required amount they need to drink; it suffices for them to just drink a sip.)
The common practice is that the bride and groom answer "Amen" to both Berachot recited by the Mesader Kiddushin, and they sip the wine relying on the Beracha of "Ha’gefen" recited by the Rabbi, to which they had answered "Amen."
There is, however, an interesting Halachic dilemma that arises regarding this widely accepted procedure. According to the Rambam (Rabbi Moshe Maimonides, Spain-Egypt, 1135-1204), the Beracha of Birkat Erusin is defined as a Birkat Ha’misva, a Beracha recited over the performance of a Misva. According to the Rambam, a Beracha is recited before the act of Kiddushin just as a Beracha is recited before one eats in the Succa, takes a Lulab, and wears Tefillin. And since it is the groom who has a Misva to get married, Birkat Erusin is, essentially, his Beracha. Meaning, he should be reciting this Beracha just as a man recites a Beracha before performing the Misva of Tefillin. Indeed, in earlier generations, the groom personally recited Birkat Erusin before performing the act of Kiddushin under the Hupa. It was only due to the concern not to embarrass those who are unfamiliar with the Beracha that the Rabbis instituted the custom that the Mesader Kiddushin recites the Beracha on the groom’s behalf. Fundamentally, however, this is the groom’s Beracha.
It turns out, then, that Birkat Erusin does not directly relate to the bride. This Beracha is recited on the groom’s behalf, and is not her obligation at all. As such, it might seem that the bride’s response of "Amen" to Birkat Erusin constitutes a "Hefsek" – interruption – between the Beracha recited over the wine and her drinking the wine. Since the Birkat Erusin has no Halachic relevance to her, her "Amen" response is no different than a response of "Amen" to anyone else’s Beracha. A person may not make any verbal interruption between the Beracha over food and eating by speaking in unrelated matters, and it thus seems that if the bride answers "Amen" to the Birkat Erusin, she must then recite a new Beracha of "Ha’gefen" before drinking the wine.
The same question arises on Succot. Women are exempt from the Misva of Succa, and thus the Beracha of "Lesheb Ba’succa" recited after Kiddush on Succot does not relate to them. Accordingly, Hacham Ovadia Yosef rules that if a woman answers "Amen" to the Beracha of "Lesheb Ba’succa," she must recite her own Beracha of "Ha’gefen" before drinking wine. Since the Beracha of "Lesheb Ba’succa" does not relate to women, her response of "Amen" to that Beracha is considered an interruption between Kiddush and drinking. Seemingly, this ruling should apply under the Hupa, as well, and the question thus arises as to why it is universally accepted that brides recite "Amen" to the Rabbi’s Berachot and then sip the wine without reciting a new Beracha.
It should be noted that Rav Moshe Feinstein (Russia-New York, 1895-1986), in his Iggerot Moshe, claimed that whenever one answers "Amen" to a Beracha, his status is the same as the one who recited the Beracha. Thus, if the Beracha does not constitute a "Hefsek" for the person who recited it, then it does not constitute a "Hefsek" for those who answer "Amen," even if the Beracha does not directly relate to them. In Rav Moshe Feinstein’s view, then, women may answer "Amen" to the Beracha of "Lesheb Ba’succa" on Succot and then drink the wine without reciting a Beracha, and this would apply to a bride under the Huppa, as well.
However, as mentioned, this is not the view of Hacham Ovadia Yosef, and we are thus left with the question of why brides answer "Amen" to Birkat Erusin and then drink the wine without reciting a new Beracha.
An answer that could be suggested emerges from a comment of the Ran (Rabbenu Nissim of Gerona, 1320-1376) in Masechet Kiddushin. The Ran writes that although women are not technically commanded with regard to the Misva of marriage, the bride has the status of Mesaye’a – one who facilitates the Misva. Quite obviously, a man cannot fulfill the Misva of marriage without a bride. As such, she plays a crucial role in the Misva, and this suffices to establish the relevance of Birkat Erusin to her, as well. And thus since the Beracha relates to the bride by virtue of her involvement in the Misva, her response of "Amen" does not constitute a "Hefsek."
We may also take into account the view of the Rosh (Rabbenu Asher Ben Yehiel, Germany-Spain, 1250-1327), who disagreed with the Rambam in classifying the Birkat Erusin. According to the Rosh, this Beracha is defined as a Birkat Shebah, a blessing to express praise to the Almighty for the festive occasion of a wedding, and does not relate to the Misva of Kiddushin. In his view, this Beracha is certainly as relevant to the bride as it is to the groom, and thus her response of "Amen" would not be considered a "Hefsek."
Hence, there is sufficient Halachic basis to justify the commonly accepted practice that both the groom and the bride answer "Amen" to the Rabbi’s Berachot and then sip the wine without reciting a new Beracha.
Summary: At the wedding ceremony, it is customary that both the bride and the groom answer "Amen" to the Rabbi’s Berachot, and they then sip the wine without reciting a new Beracha.
