Making a new “layshayv baSukkah” when going to a friend’s Sukkah is quite complicated. There are many opinions (including Rav Moshe Feinstein and Rav Shlomo Zalmon Aurbach) that a berachah should be made even if nothing is eaten (according to all shittos). Others argue.
That is without a previous berachah in one’s own Sukkah.
If one goes from his Sukkah to a friend’s Sukkah, there is an entirely different shaylah of making a new berachah.
If one had in mind that he would be going when he made his original berachah, MB rules not to make a new berachah.
If he did not have this in mind:
- MB seems to rule to avoid that situation
- Rav Elyashiv ruled no berachah
- Shevet HaLevi ruled to make a berachah
- If Rav Malinowitz were forced to rule, he would rule to make a berachah.
Lema’aseh, Rav Malinowitz says to read over the first paragraph. And so if you go a friend’s sukkah after making a “layshayv baSukkah” in your own sukkah without any particular thought of going to this new sukkah:
- If you eat a shiur of mezonos which requires a berachah in a Sukkah, make a new berachah.
- If you don’t eat a shiur of mezonos, then don’t make a new berachah.