They did not store the wine in large casks but in small barrels, because if it was in a large cask, the taste of the wine would be weakened. A large cask stored a tremendous amount of wine, and they would open it repeatedly to pour out some wine to be used. Every time they opened it, air would enter the barrel or cask and weaken the taste of the wine. Small barrels, however, were usually emptied in one shot. Whenever one was opened, it was emptied right away and used, so the taste of the wine would be better preserved.
They also would not fill the wine barrels all the way to the top, up to the mouth, so that the wine's aroma wouldn't... It would be strong. When a person filled the barrel all the way to the top, there was no air above the wine, and the air produced by the fermentation of the wine would sort of leave the barrel. It would leave the cask, and it would lose some of its fragrance and taste. But when you left a little bit of a gap right above the wine and didn't fill the barrel or cask all the way to the top, the fumes of the wine would stay in the barrel and create that great taste that was there. The aroma would stay very strong.
When a person removes wine from a barrel of nesachim (libations), he shouldn't take it from the top of the barrel, because there is mold there. There were flour-like particles that would rise to the surface of the wine, which was considered to be mold. So he shouldn't take wine from there when using it for the nesachim. He also shouldn't take wine from the bottom of the barrel, because sediment had collected there, and that was considered unappetizing. What he should do is take wine from the barrel's middle third, and he should take it from the middle of that third. That's the spot in the barrel from which he should take the wine.
To take wine out of the barrel, they would take a spigot and push it into the middle of the barrel's wall, and wine would come out into a container. We'll talk about how the wine was examined as it flowed from that spigot. How would the person examine it? How would he examine the wine coming out for impurities?
The treasurer of the Beit HaMikdash (Holy Temple) would sit with a reed in his hand. The reed would be used as a measuring stick to see what was going on. When the barrel discharged sediment, he would use a reed to knock the spigot from which the wine was coming out and push the flow of wine away, so that the sediment wouldn't mix with the pure wine that had already flowed into the container. So he would sort of plug it up. He would divert the wine from coming in, and it would go in a different direction.
We earlier learned that a Kohen (priest) shouldn't take wine from the top of the barrel because there was mold there. The next Tana (tannaitic sage) is going to be more strict. Rabbi Yosei bar Rabbi Yehuda—the son of Rabbi Yehuda—says that wine that grew mold is invalid to be used as nesachim. Shene'emar (as it says): temimim yihyu lachem u'minchatam, unblemished should they be for you and for the menachot (meal offerings). The Pasuk (verse) says, “Unblemished should they be for you and for the menachot,” temimim yihyu lachem, and also unblemished they should be for you and their nesachim. So we say, just as an animal for a korban (sacrifice) has to be unblemished, ingredients for the menachot and the nesachim have to be unblemished as well. If the barrel of wine contains any mold, then the entire barrel is considered blemished, and the entire barrel cannot be used. So using the middle section would still be a problem if the top was moldy, according to the opinion here of Rabbi Yosei.
This is in contrast to the opinion of the Tana Kama (first tanna), who said you could just use the middle here. What Rabbi Yosei and Rabbi Yehuda are saying is that the entire barrel cannot be used if there was some mold in it.