The "Wine Quest" refers to the misc objective that states: "Locate the hidden stash of Emberbrand Wine in Raven Rock" in Skyrim: Dragonborn
It is a Miscellaneous Quest that starts at Raven Rock after March of the Dead
Speak with Captain Veleth and he tells you that he has a problem with his guards getting drunk from Emberbrand Wine. He wants you to Locate the hidden stash of Emberbrand Wine in Raven Rock
Tutorial for finding Emberbrand Wine Stash[edit]
Go to this abandoned house (marked on the map below with an "X"):
Another map to help you find the location:
Find this small alley where the ruinded foundations of some homes are:
Then just loot Barrel to get the Emberbrand Wine:
Here is what it looks like: