daf bit: Avodah Zarah 66

[cellio]

Yayin nesech is wine that has been used for idolatry. We can't drink it or even benefit from it because it's tainted. What if it is spilled on or into something else -- does that taint the mixture too? Does it matter what the effect was? The g'mara discusses several cases -- wine spilled onto grapes (are they cut or whole?), wine spilled onto wheat (does it absorb?), and more. The mishna gives a general rule: whatever gains an advantage because the wine imparted a flavor is prohibited; whatever does not gain an advantage through flavor is permitted. In the g'mara, R' Abbahu in the name of R' Yochanan, along with others, says that if the wine improves the flavor of the other item the mixture is prohibited, but if it makes it taste worse it's ok. R' Meir, however, says that whether it imparts a better or worse flavor, it is forbidden, because we're prohibited from eating from gentiles' cooking vessels even though they impart a worse flavor to their contents because they're used for things like non-kosher meat. (65b-67b)