More than Mom's apple pie, peanut butter is the all-American food. With its rich, roasted-peanut aroma and flavor; caramel hue; and gooey, consoling texture, peanut butter is an enduring favorite, found in the pantries of at least 75 percent of American kitchens. Americans eat more than a billion pounds a year. According to the Southern Peanut Growers, a trade group, that's enough to coat the floor of the Grand Canyon (although the association doesn't say to what height).

Americans spoon it out of the jar, eat it in sandwiches by itself or with its bread-fellow jelly, and devour it with...