Pepper is the world's most popular spice, yet many cooks today don't appreciate its plentiful and inexpensive supply. Pepper was once so valuable and rare, that it was even used as currency! Peppercorns are berries that grow in grape-like clusters on a pepper plant and are processed to produce the three basic types of peppercorns: black, white, and green. Black peppercorns are the strongest in flavor of the three, being slightly hot, but with a hint of sweetness. White peppercorns are ripened and their skin is removed, making them more mild than the black variety. Green peppercorns are under ripe berries that are usually preserved in brine.