In order to preserve the freshness of grapes as long as possible, you will want to put them in your refrigerator as soon as you get them home from the store.

Make sure to keep your grapes in the vegetable crisper or some other sealed container within the fridge so that they can stay fresh for a while. By doing this you will give yourself the chance to eat all of them before they start taking on a mushy texture and go bad.

If you want to save your grapes for a while until you can eat them, you might want to think about putting them in the freezer.