Along the Inquisitor's quest line he will task you with bringing him 20 firewood and 10 flyers. After doing that he will give you permission to use the vineyard West of Witch Hill. You can purchase grape seeds from Merchant in the Village on the day of Gluttony. He sells seeds for all 3 qualities, for this achievement you will want the gold star seeds. Fertilize your soil with peat and plant the gold star seeds. They take just under a week to produce grapes. You then put 15 gold quality grapes into the Vine Press (unlocked in tech tree). That will give you a pale of gold quality grape juice. You then put 2 pales of gold quality grape juice into Winemaking Barrel (unlocked in tech tree and built in the cellar). When you open the Winemaking Barrel it will default set to bronze quality juice, scroll both tabs up to gold quality to make the wine for this achievement. There is a meter on the left of the Winemaking Barrel tab that tells you your chances of making gold quality wine. If you don't get it on your first try, repeat the process. Good luck!