The farmers' markets are wide open, and I am having fruit envy. I have been surrounded by strawberries, cherries, and other early summer fruit, and I want to bring it all home with me! But I can't eat all that fruit, and I don't have time to can it all either. So I will most likely freeze some, then turn to the easiest, simplest, most long-lasting way to preserve the flavor of fresh summer fruit: Fruit vinegar. Here's why.