Green, white and Black pepper (Piper nigrum) are all products of the same plant but each is harvested and handled differently.
The world is familiar with Black and White Pepper but not so with Green Pepper which is becoming increasingly difficult to obtain.
The berries grow in spikey clusters on vines that reach 30 feet or more. The vines are cultivated on small plots that must be tended to carefully. The vine is trained to grow onto support posts, regular weeding and fertilisers are mandatory and shade from the sun is sometimes necessary. They are finicky plants, subject to blight which stops them from being planted again in the same spot blight has struck.
A vine will not yield a crop until after the third year and does not go into full production until around the seventh year. The clustered spikes of perhaps 50 berries are hand-picked at just the right time for the desired black, white or green peppercorns.
The finest black pepper is said to be Tellicherry from India because they are larger and have the most flavour.
Black pepper is produced from the still-green, unripe drupes which are briefly cooked in hot water, both to clean them and to prepare them for drying; the heat ruptures cells in the pepper, speeding the work of browning enzymes during drying. The drupes are dried in the sun or by machine for several days, during which the pepper around the seed shrinks and darkens into a thin, wrinkled black layer. Once dried, the spice is called black peppercorn.
White pepper consists solely of the seed of the pepper plant, with the darker-coloured skin of the pepper fruit removed. This is usually accomplished by a process known as retting where fully ripe red pepper berries are soaked in water for about a week, during which the flesh of the pepper softens and decomposes. Rubbing then removes what remains of the fruit, and the naked seed is dried.
Green pepper, like black, is made from the unripe drupes. Dried green peppercorns are treated in a way that retains the green colour, such as shade drying.