White pepper consists of the seed of the pepper plant alone, 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. Sometimes alternative processes are used for removing the outer pepper from the seed, including removing the outer layer through mechanical, chemical or biological methods.
Ground white pepper is often used in cream sauces, Chinese and Thai cuisine, and dishes like salad, light-coloured sauces and mashed potatoes, where black pepper would visibly stand out. White pepper has a slightly different flavour from black pepper, due to the lack of certain compounds present in the outer fruit layer of the drupe, but not found in the seed.
Black pepper (Piper nigrum) is a flowering vine in the family Piperaceae, cultivated for its fruit, which is usually dried and used as a spice and seasoning. When dried, the fruit is known as a peppercorn. When fresh and fully mature, it is approximately 5 millimetres (0.20 in) in diameter, dark red, and, like all drupes, contains a single seed. Peppercorns, and the ground pepper derived from them, may be described simply as pepper, or more precisely as black pepper (cooked and dried unripe fruit), green pepper (dried unripe fruit) and white pepper (ripe fruit seeds).
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. It is one of the most common spices added to cuisines around the world. The spiciness of black pepper is due to the chemical piperine, not to be confused with the capsaicin characteristic of chili peppers. Black pepper is ubiquitous in the modern world as a seasoning and is often paired with salt.