Avodah Zarah 5:10-11

Avodah Zara 5:10

If non-Jewish wine fell into a vat of kosher wine, all of it is prohibited for benefit. Rabban Shimon ben Gamliel says that it may be sold in its entirety to a non-Jew, minus the value of the non-Jewish wine in the mixture.

Avodah Zara 5:11

Let’s say that there’s a stone wine vat that a non-Jew has coated with tar (which may contain wine to mask the odor). The Jew may wipe down the vat and it is fit for use. Regarding a wooden vat, Rebbi says he may wipe it down but the Sages say that he must peel off the tar. An earthenware vat is prohibited even if he peels off the tar.