A recipe requires a litre of white grape concentrate, but I can't seem to find any in my area. I assume it would be possible to use 100% grape juice instead? If so, what would the quantity needed be? For example, 1 litre of concentrate + 8 litres of water would become something like 2 litres of grape juice + 7 litres of water?
Any advice would be greatly appreciated.
BTW this is for peach wine, and the peaches are about to be shipped so this is kind of an emergency.