Capers are the tiny, unopened flower buds of the spiny caper bush, hand-picked before they bloom and almost never eaten raw — curing in salt, brine or vinegar transforms a bitter, grassy green nub into the sharp, tangy, mustardy-floral pop that brightens puttanesca, chicken piccata, tartare sauce and a plate of smoked salmon. Smaller, tighter buds are the most prized; the larger berry-like caperberries are the bush's fruit, eaten stem and all.