Verjuice is made from the juice of unripe grapes, which is pressed from a green harvest done earlier in the season. The key here is unfermented grape juice (wine vinegar has to come from fermented grape juice) Its main purpose would be culinary but recently its also found it way into cocktails.
So its incredibly zippy stuff but it also has a lovely ripeness and richness about it. am not saying you could drink it but it is pretty tasty stuff neat. It would be ideal used instead of vinegar in a dressing or just drizzled on top of any dish looking for some zing.