First I was an Episcopal priest.
Then we came to Virginia and I worked for two years in a real vineyard (and was told I was persnickety enough to make a good winemaker).
Then I was a shepherd.
Now I'm a Catholic; and I could have saved a lot of sturm und drang if I'd started there. But my work as vineyard laborer and shepherd opened up parts of Scripture as no amount of exegesis could do.
Mind you, the Jews did not realize that the same stuff that made dough rise also made wine ferment. If they did, it would mess up having wine at Passover, when all leaven is to be eschewed. I BELIEVE, but do not know, that to this day instead of pitching must with yeast they pitch with must from a previous vintage.
But it is the ubiquity of wild yeast that made fermented drink available at first, I suppose. I'm guessing mead first -- some guy comes across some honey diluted by rain and then fermented. He's desperate so he drinks some. He notices that suddenly a lot of women look really good, so he tries to repeat the experience.
Or one can imagine how the liquor from accidentally sprouted and rained upon grain might be drunk in similar desperation. And the stuff on the neanderthal big screen TV is suddenly less irritating.
The next day, when he's done with his hangover, he naturally says, "Hey, maybe we can do that again!"
Beer nuts are a later development.
I thought the yeast on the grape skin was sufficient for fermentation. I grant that I know almost nothing about it -- mostly something in a Sam Levenson book where he describes his parents making wine for Passover; he only mentions their adding sugar and water. (Of course, he wasn't writing instructions -- just explaining how they came out with so much as his father kept adding sugar because it wasn't sweet enough and his mother kept adding water because it was too sweet!)