Masechet Avodah Zarah (idol worship), Perek Dalet, Mishnah Chet.
At this point in the Masechet, we will transition to talk about Yayin Nesech. We're not going to be talking about idols anymore in Avodah Zarah. We'll now focus on Yayin Nesech, which is wine that was poured as a libation to an idol. All types of offerings that were brought for an idol become prohibited to benefit from on a Torah level. Not only wine, anything. Anything that was brought as an offering is prohibited. Wine specifically was commonly used as a libation to idols. Therefore, Chachamim (Sages), or the Torah, really, discussed the prohibition that all Yayin Nesech—all wine that was poured as a libation—is prohibited de'oraita (on a Torah level).
Chachamim extended that to all wine owned by a non-Jew, stam yeinam (ordinary non-Jewish wine). All wine that was owned by a non-Jew is prohibited to benefit from on a derabanan (by rabbinic decree) level because Chachamim were nervous that maybe the wine was really used for idol worship purposes and we don't know it. Especially, the custom at the time was that after they had completed a wine barrel, they would splash some off the top of it as a thank-you to their gods. So that shows many, many types of wine were used in the service of Avodah Zarah, even if a person didn't know it. So therefore, Chachamim said regular wine becomes prohibited as well.
Chachamim also said that let's say somebody was a monotheist. They didn't worship idols. They only believed in Hashem. Their wine becomes prohibited as well because part of the reason that Chachamim set this prohibition is to make sure that there was a distance between the Jew and the Gentile, that there wasn't socializing between the two of them, to prevent intermarriage. Also, if a non-Jew put his finger in the wine, for example, and stirred it, it could be that even that type of stirring, that type of wine movement, was for Avodah Zarah purposes, as an offering to the idols. So therefore, all types of wine that were handled by a non-Jew, even if it was owned by a Jew, become prohibited on a derabanan level, aside from the Yayin Nesech that was poured straight up for the Avodah Zarah, which is de'oraita.
Chachamim also said that's only wine. For something that's mevushal, wine that was boiled, the chashuv level, the honorable level of that wine, was now removed because it's boiled wine, it's cooked wine. It's not ra'ui, not befitting to pour on the Mizbeach (altar). A non-Jew wouldn't use that in their service of Avodah Zarah. So, Yayin Mevushal is permissible for a non-Jew to handle.
Grape juice as well is considered to be wine for the purposes of stam yeinam. If a non-Jew touched grape juice at a certain point in the processing, that would also be prohibited because of stam yeinam. Here the Mishnah will tell us what that point is. When is it considered to be grape juice, as opposed to just actual grapes that are still allowed? The Mishnah will tell us at what point in the process it becomes asur (prohibited).
The Mishnah says you're allowed to buy the crushed grapes from the wine press of an idol worshipper, even though he crushed them with his feet. Just a little background on how they would make wine in the times of the Mishnah. They would have a circular thing on top, like a cistern where they would put all the grapes, step on them, and crush them with their feet. Then the wine or grape juice at this point would drip down a sloped wooden plank into a pipe, and then pour out of that pipe into another type of cistern on the bottom, another type of bowl that would catch the wine.
So what we're saying here is they would take grapes and put them on top, then smash them and allow the grape juice to flow down. So you're permitted to take the grapes that are on top, even though they were crushed and even though grape juice flowed from them. Even though the idol worshipper takes the crushed grapes out of the juice with his hand and places them on the mound, the flat area on the top of the wine press, so that they would continue to drain, you're allowed to take them. What we're talking about is that they're not down into the pipe area yet, into the bottom cistern. It's all on top. At that point in time, you're allowed to take the grapes and even the grape juice that would be with them. It doesn't become subject to the laws and the prohibition of Yayin Nesech until it flows down into the bottom of the wine press, into the bor, into the pit. Only at that point in time is the juice considered to be wine.
“Yarad la-bor, mah she-ba-bor asur, veha-she'ar mutar” (When it goes down to the pit, what is in the pit is forbidden, and the rest is permitted). Once the juice has flowed into the bottom bor, into the pit on the bottom, whatever's in that bor, that pit, that cistern, becomes prohibited once the idol worshipper touches it, because now it's considered to be wine. Veha-she'ar mutar. And the remainder, the juice that's on top of the wine press, in the top cistern and on the wooden plank that hasn't flowed down into the bor yet, into the bottom cistern, would be permitted for drinking even if the idol worshipper touched it, because it's not considered to be wine.
To summarize, whatever is not in the bottom bor, the cistern, yet, even though there may be juice involved, is not considered to be complete grape juice/wine. So a person's allowed to benefit from it even if an idol worshipper touched it. But whatever has reached that bor, that cistern, is considered to be wine, grape juice, and you're not allowed to benefit from it once an idol worshipper touched it.