2,390. Wine From an Earthenware Cup

Maachalos Assuros 11:18

It is likewise prohibited to drink from an earthenware vessel from which an idolator had drunk wine unless it was thoroughly rinsed three times. If this is done, it is permitted because all traces of wine have been removed. This is only the case, however, if the cup is glazed with lead or coated with pitch. If it’s simply earthenware, then only one thorough rinsing is required.

Maachalos Assuros 11:19

When earthenware vessels glazed with lead are used for non-Jewish wine, they remain permitted if they’re white, red or black; they’re prohibited if they’re green because such vessels are absorbent. If there’s a spot where the earthenware shows, they’re prohibited whether they’re white or green because they absorb. The Rambam opines that this is only the case when wine was put in them for a long time; if it was only in them for a short time, then only rinsing them is necessary. The vessels are then permitted even if they’re earthenware.