Capers, those little olive-green bursts of slightly bitter acidity that light up a number of dishes from Sicily, are the flower buds of Capparis spinosa, a Mediterranean shrub found in France and Spain, as well as southern Italy. Caper buds are picked before flowering into maturity and sun-dried. They get their characteristic taste as a result of a pickling process, which causes the formation of capric acid. The tiniest buds, packaged mainly in France, are the most prized, purported to have the best flavor and texture. Caper berries are the mature fruit of the same shrub, and are more common in Spain and Italy than in France. Slightly larger than a grape, with faint white stripes on their pale olive skin, caper berries are used and eaten in a manner similar to brined olives. The flavor of the caper berry is similar to that of the caper, only far less intense.
Both capers and caper berries should be rinsed and drained to remove excess brine or salt before use in cooking. Capers are often added to sauces and condiments to add a briny piquancy. They are particularly well-suited for use with seafood, and are commonly paired with salt cod and mutton.