This Mishnah is going to talk about an idol worshiper who was eating at the home of a Jew. The Jew stepped out of the room, leaving the idol worshiper alone with the wine. The Mishnah says that if the Jew was eating with an idol worshiper at the main table in the home of a Jew, and the Jew placed a jug of wine on the main table and a jug of wine on the side table, the setup in those days was that the main table was sort of where everyone could take food from. That was the buffet that was pretty much open to all the guests. They could come and serve themselves from that main table. But the side table was for food in reserve, food that was in the back, food that wasn't for everybody. The idol worshiper would normally feel comfortable serving himself from the main table, and the Jew would serve himself from the main table, but not from that side table. The Jew left the room, leaving the idol worshiper there alone with everything else.
The wine on the dining room table—the main table, from which the goy (idol worshiper) would have felt comfortable taking food—is prohibited. What was on the side table is permitted. The idol worshiper, who was a guest in this house, as we said, would feel free to touch the wine that was on the dining room table, and therefore that wine would be forbidden. But he wouldn't feel comfortable taking the wine that was on the side table, because guests normally don't take from there. Therefore, that wine is permitted. You could assume he didn't touch it.
But if the Jew told the idol worshiper before he left, “Take some wine, pour yourself a drink,” the idol worshiper basically understands that it's permission for him to take wine from anywhere, even from that side table. So the wine on the side table is prohibited as well. If he told him that—“Come take wine from anywhere”—and the idol worshiper understood that he could take, really, from the whole house, what happens to the rest of the wine in the house? Chaviyot petuchot asurot. Wine that was in open barrels is prohibited because it's possible that the idol worshiper took from there. Setumot, if there were sealed barrels in the house, those are only prohibited if the idol worshiper was alone with those bottles.
Sheyiftach veyigof vetigov: long enough for him to open the seal, make a new seal, and then allow that seal to dry up before the Jew returns. That would be the minimum amount of time for it to appear closed now. But if that didn't happen, then you could assume those closed bottles were not opened, because they're closed in front of us. If they were open, they wouldn't have had time. He wouldn't have had time to close the roll up. So we can make the assumption that they were never opened.