2,388. Vessels That Held Non-Jewish Wine

Maachalos Assuros 11:14

Non-Jewish grape seeds and skins are prohibited for 12 months. After that, they’ve completely dried out and may be eaten. Similarly, wine dregs that have dried out may be eaten after 12 months; since no wine remains in them, they’re just like dust and dirt.

Maachalos Assuros 11:15

It is prohibited to put wine into skins or barrels where non-Jews kept wine until one of the following three conditions has been met: the skins or barrels are left to dry for 12 months; or they’re put in fire until their pitch softens or they get hot; or water is put in them for three full 24-hour period, changing the water every 24 hours for three days. The same applies regardless of whether the vessels belong to the non-Jews or to a Jew from whom they were borrowed. If wine was put in these vessels before purifying them, it may not be drunk.