In honor our of my spouses fathers Yartziet we donated a new kiddish cup. The cup is silver and has a plastic insert to protect the inside from the acid of the wine. We purchased the one with a custom plastic liner because the last two kiddish cups rotted inside because of the wine acidity. Everyone was happy with the new cup except one person that made a fuss. He said halacha demands silver only. Is there any halacha or poskim that demands that the cup be only silver? I have watched many people make kiddish with a plastic cup. Thank you so much!
If the plastic is attached to the cup, there is definitely nothing wrong with using the cup for kiddush, and it is kasher to make kiddush in it according to all poskim. There are poskim that were sceptical about using a disposable plastic cup, but that would not apply here, because it is a regular kiddush cup with a layer of plastic. There are however certain preferences to using a silver cup. The main preference is because it is hidur mitzva, because the cup is more elegant. Others say that silver is special for kabalistic reasons, however even so, essentially this cup is a silver cup, with the plastic lining serving as a protection for the silver. This idea has been verified with Horav Yackov HIllel shlit”a, Rosh Yeshiva of Ahavat Shalom.
In the pictures that you sent it is clear that the plastic detaches, so we can’t say clearly that the plastic is a part of the silver cup. Nevertheless you may still use the cup for Kiddush without any problem. You are yotza kiddush when using only the plastic part of the cup, even if you wouldn’t put in into the silver part. Years ago there was controversy regarding using a paper cup for Kiddush. This would not apply to your cup, which is made of thick plastic, since it can hold the wine in it without it leaking out, and it is not disposable. Using the silver cup with the plastic insert would also be hiddur mitzvah, since it looks very nice and regal. Therefore halachically it is fine without any issue. Regarding the kabalah aspect of it, since the plastic does detach, it isn’t clear to me if we look at the plastic as a mere part of the silver cup or not, since it is made to be part of the silver cup. Therefore there is no problem using the cup for Kiddush.
Be’er Moshe 3-55, 5-42, Tzitz Eliezer 12-23, Shmiras Shabbos Khilchoso 47 ftnt 51, Mbais Levi vol.3 pg. 70, Kuntis Yad Dodi- Kiddush-2, Meohr Hashabbos 4- pg. 558, Aliba D‘hilchoso vol. 31 pg.68 column 4. Mekor Chaim 182-1, Kaf Hachayim 472-11