Q&A from the Bais HaVaad Halacha Hotline

A Shvacheh Cup

March 7, 2024

Q Are disposable cups suitable for kiddush or havdalah?

A Disposable utensils are a relatively new product, and much has been written about their status in various areas of halacha.

Kiddush and havdalah, like certain other brachos, require a kos shel bracha—a cup of wine must be held during their recitation and subsequently drunk. The Gemara (Brachos 51a) enumerates the requirements of a kos shel bracha, one of which is completeness (following Tosfos ibid. 50b s.v. Modim). R’ Moshe deduces from this that the cup must be substantial, and he reasons that a cup that is tossed after use doesn’t meet this standard.

R’ Shlomo Zalman Auerbach disagrees, arguing that a disposable cup is fit for longer-term use, and it is discarded only because of its low value (Shulchan Shlomo 18 n. 13), so it is suitable for kos shel bracha. R’ Nissim Karelitz differentiates between flimsy cups that are used only once and sturdier ones that can be reused several times (Chut Shani 85 note 7).

Stacking together two or three invalid cups doesn’t help (see Piskei Teshuvos 159 n. 7 regarding netilas yadayim).

All agree that if no other cup is available, disposables may be used. Even a broken cup is valid if there is no alternative (Mishnah Brurah 183:10).

If a cup is cracked and leaks wine, and the crack is low enough on the cup’s side that the leak will eventually reduce its content to less than a revi’is, it is invalid even bedieved, and kiddush or havdalah may not be recited until a substitute is obtained (Sha’ar Hatziyun 183:14).