If you’re faced with a bunch of grapes that turn out to be too sour for eating out of hand, here are some ideas for using them:
Freeze them and eat frozen for a tart snack.
Add them to a green salad, or to a fruit salad tossed with orange juice to sweeten it up.
Toss them with a little olive oil, salt, and pepper and roast them to bring out their sugar; drizzle with balsamic vinegar before serving.
Saute them with onions or shallots, add a little rosemary, and serve with sausages on soft polenta.
Add them to an Indian curry.