What do beer, cheese, yogurt, sauerkraut, miso, jam, even chocolate--I'll bet you didn't know--have in common? They are all preserved foods. Artisanal canned tomatoes and homemade kimchee might be trendy items now, but they come from a culinary need as old as human civilization itself. Can It! celebrates those transformed and transforming foods that have done so much to create the diversity of cuisines found around the world, bringing readers on a tangy adventure of all the ways necessity has bred deliciousness.             Food preservation rests in a simple problem: food tends to come in concentrated periods of abundance and then quickly spoil. Today we might pump it full of preservatives or throw it in the freezer, but for most of our time eating the things that the earth provides, we haven't had these luxuries. As Allen shows, that's been a wonderful limitation: our ancestors, knowing next to nothing about organic chemistry, found consistent techniques not only to preserve the foods they grew but to alter them--to delicious effects. Wine is more than old grape juice, cheese more than spoiled milk. Allen details how these transformations resulted in new flavors, textures, and, ultimately, new ways of defining the tastes and culture of a community, which passed down its knowledge from generation to generation. Exploring the history and science of preservation, he examines all the major techniques--from drying to smoking to salting to canning to fermentation--reveling in the cornucopia of different foods they have produced. Allaying the fears of the squeamish, he serves up easy-to-do historic and modern recipes that will help any home cook participate in one of culinary history's most hallowed traditions.