Throughout the medieval Europe, pepper was commonly traded, oz. for oz., for gold. This irreplaceable spice has long been recognized as an ingredient for stimulating the appetite. Peppercorns can be, depending on their processing, either black, white, green and red.that is, the same plant produces all four types, depending on the time of harvest and the method of processing. Black pepper is harvested nearly ripe and dried at a moderate temprature.