"It must be potent wine to make a wood-elf drowsy; but this wine, it would seem, was the heady vintage of the great gardens of Dorwinion, not meant for his soldiers or his servants, but for the king's feasts only, and for smaller bowls not for the butler's great flagons."
Douglas A. Anderson, in the excellent Annotated Hobbit, explains:
"The name Dorwinion is clearly of Elvish origin, and it appears in Tolkien's earlier writings. In "The Lay of the Children of Húrin", a long unfinished alliterative poem written in the early to mid-1920s, the especially potent wine of Dor-Winion [sic] is described as coming from the burning South, which implies that Dor-Winion is located in Beleriand. [...]
Dorwinion also appears in a text probably dating from the mid-1930s, just before Tolkien began writing The Lord of the Rings in December 1937. This text is the conclusion to the Quenya Silmarillion (published in volume five of the History, The Lost Road), and "the undying flowers in the meads of Dorwinion" are mentioned in the final paragraph, implying that Dorwinion is overseas in Tol Eressëa.
Finally, on Pauline bayne's Map of Middle Earth (1970), which was compiled with Tolkien's assistance, Dorwinion is placed on the northwest shores of the inland Sea of Rhûn, far down the banks of the River Running in the East. The placement here certainly accords with the mentions of Dorwinion in The Hobbit but does not account for the appearance of the name in earlier texts."
Well, that's good to know. But what about the wine?
I would like to nominate one of my favorite wines to the rank of "Wines from Dorwinion":
HoneyRun Winery's Blackberry Honeywine
This is a double whammy - without a doubt the best blackberry wine I have ever tasted, as well as the best mead (there was some homebrew mead that Mrs. Meadows and I were given many, many years ago, but that's a different story, kids!)
Because of various laws, this product is sadly not available everywhere, but if you are in one of the "allowed" states, you can order it here: HoneyRun Winery.
If you can get your hands on a bottle (keep it over 21, folks!), I highly recommend and encourage you to do so.