Why did Noach plant a vineyard?

Question

The first mention the torah makes of wine and vineyards is in Gen 9:20-21, when Noach plants a vineyard and then gets drunk on wine after the flood. What prompted him to plant a vineyard as, apparently, his first agricultural project, and did he know that he would become intoxicated? Or was that result an accident and alcohol was previously unknown in the world?

Rashi says (on 9:20) that he brought vine branches into the ark with him, suggesting that grape vines weren't new, but that doesn't answer the question about the intoxicating effects. (Maybe previously they only ate the grapes and didn't ferment them.)

Answer 1

The Talmud (Sanhedrin end of 70a) alludes to Adam drinking wine - although it isn't exactly clear how that would work given the time frame - saying that Noach should have stayed away from wine, learning from Adam with the sin of the Eitz Hadaas which was caused by wine - according to the opinion that the tree was a grape vine.

Answer 2

The Shelah HaKadosh writes in parshas Noach that Noach planted a vineyard because he wanted to repair (the Zohar vol 1, 73a says "to understand") the sin commited by Adam, but instead, he failed to do so.

On regard the 2nd question, I assume that was an accident since Radak to 9:20 says that until that time people planted grapes only as a fruit to eat, and had not learned how to make intoxicating wine:

כי עד הנה לא היו שותים יין אלא אוכלים הענבים כשאר הפירות:

Answer 3

I was taught that either he was celebrating his survival, or depressed because of everyone else's death -- both reasons people turn to alcohol.

Answer 4

Ralbag in his commentary there writes as follows:

ואמר שכבר התחיל נח ליטע כרם לתכלית שיעשה ממנו יין כי חכם גדול היה בעבודת האדמה כמו שקדם ולזה אמרו רז"ל בב"ר בו ביום נטע בו ביום שתה ר"ל שהוא נטעו לזה התכלית

And it says that Noah already began to plant a vineyard for the purpose of making wine from it, for he was a very wise man in the field of agriculture as mentioned previously. And this is why the Sages of blessed memory in Bereishit Rabbah said: "on that day he planted it and on that day he drank" – meaning to say that he planted it for this purpose.