An Unfermented wine is created when a player with a cooking level of 35 or more uses grapes with a jug of water. After 12 seconds, this item will automatically turn to either a jug of wine or a jug of bad wine, giving 200 cooking experience for the former situation and none at all for the latter. The player will also stop making bad wine at level 68 cooking.
A player creating a jug of wine.
Wine ferments on a global 12 second timer that resets each time you make a new jug of unfermented wine, whether banked or in your inventory. This means a large stack of wine in your bank can ferment all at once.