Rock Grapes

I almost didn't consider using these grapes if I'm gonna be honest. Then on a whim, I experimented with them and discovered the cool effect they have on the wine produced from them. 

— Orion Starbreeze in an interview about his brewing business.

Native to the Underdark, these grapes are found in caves and other subterranean places. They do not need much light and their vines climb up the rocky cavern walls as they grow. Dark elves really enjoy their flavor and now cultivate them in underground "vineyards". They are most popular when turned into wine.
Cheap and easy to grow, they are enjoyed by people of all ages. Children especially love the sweet jams they are turned into or even freeze a bunch to eat on a hot day. They have a lighter flavor than normal grapes mixed with a hint of plum. There are also seedless and more tart varieties available as well. Many markets in the Underdark have them stocked for sale.

Type: Fruit 
Discovered: 239 
Color: They come in two varieties: Ghost White and Pale Gray. 
Shape: Typically round, but can also grow into lumpier forms. This does not usually affect the quality or taste.
Size: 1.5 inches in diameter. 
Rarity: Common

Uses

These grapes are edible and used primarily in food products. People enjoy them fresh off the vine, juiced, dried, and turned into wine. Dark elves enjoy turning them into preserves to spread on fresh baked rolls or to marinate mushrooms in before grilling.