Recipe (3 Gallons)
3 Litres Reg Grape Juice
3 Litres Blueberry & Cranberry Juice
2 Kg Sugar
Nutrient
2 Teaspoons Pectolase
3 Teaspoons Tartaric Acid
Gervin D Yeast
And now a gratuitous picture.
I made some movie clips of the whole process, which I'll edit together sometime. In doing so I forgot to take snap shots. By the time I remembered the washing up was done ... so that's why you have an image of 6 cartons of upside down juices ... all rinsed and ready for recycling (I'll just polish my halo :-) )
Method
Basically chuck everything into your sanitised fermenting vessel, make up to 3 gallons, measure the gravity and add a sugar or water to get it where you want it. This recipe came in at 1077, I'm happy with that so I made no adjustment. Give the whole lot a really good sloshy stir to get some air dissolved. Chuck in the yeast, cover it up, stir sloshily at least once daily for a few days then follow your normal procedure of moving to secondary vessels, racking, degassing, stabilising etc etc.
Thoughts
This is a light wine, it'll be ready to drink in as little as 6 weeks. Tho perhaps 8 is a more reasonable expectation. But as with all wine it will improve with age and you'll notice that week on week with wines like these (2 litres of juice per gallon and OG 1070-1080).
I've made an instructional vid (aimed at beginners) for starting this wine. Clicky to watch
Edit 19th Sept 2010: Final gravity turned out to be 997, meaning 10.9% ABV.