Dried ground pepper has been used since antiquity for both its flavour and as a traditional medicine. Black pepper is the world's most traded spice.

Black pepper comes from a climbing vine, the fruits of which - small round berries - ripen from green to red and finally to brown. Black peppercorns are actually berries that are picked when they're just turning red.

They are then dried whole before being sold. Peppercorns can be green, white or black, depending on when they are harvested.