Pepper gets its spicy heat mostly from piperine derived from both the outer fruit and the seed.
Black pepper contains between 4.6 and 9.7% piperine by mass, and white pepper slightly more than that.
Refined piperine, by weight, is about one percent as hot as the capsaicin found in chili peppers.
The outer fruit layer, left on black pepper, also contains aroma-contributing terpenes, including germacrene (11%), limonene (10%), pinene (10%), alpha-phellandrene (9%), and beta-caryophyllene (7%), which give citrusy, woody, and floral notes.
These scents are mostly missing in white pepper, as the fermentation and other processing removes the fruit layer (which also contains some of the spicy piperine).
Other flavours also commonly develop in this process, some of which are described as off-flavours when in excess: Primarily 3-methylindole (pig manure-like), 4-methylphenol (horse manure), 3-methylphenol (phenolic), and butyric acid (cheese).
 The aroma of pepper is attributed to rotundone (3,4,5,6,7,8-Hexahydro-3α,8α-dimethyl-5α-(1-methylethenyl)azulene-1(2H)-one), a sesquiterpene originally discovered in the tubers of Cyperus rotundus, which can be detected in concentrations of 0.4 nanograms/l in water and in wine: rotundone is also present in marjoram, oregano, rosemary, basil, thyme, and geranium, as well as in some Shiraz wines.

Pepper loses flavour and aroma through evaporation, so airtight storage helps preserve its spiciness longer.
Pepper can also lose flavour when exposed to light, which can transform piperine into nearly tasteless isochavicine.
Once ground, pepper's aromatics can evaporate quickly; most culinary sources recommend grinding whole peppercorns immediately before use for this reason.
Handheld pepper mills or grinders, which mechanically grind or crush whole peppercorns, are used for this as an alternative to pepper shakers that dispense ground pepper.
Spice mills such as pepper mills were found in European kitchens as early as the 14th century, but the mortar and pestle used earlier for crushing pepper have remained a popular method for centuries, as well.

Enhancing the flavour profile of peppercorns (including piperine and essential oils), prior to processing, has been attempted through the postharvest application of ultraviolet-C light (UV-C).
Pepper gets its spicy heat mostly from piperine derived from both the outer fruit and the seed. Black pepper contains between 4.6 and 9.7% piperine by mass, and white pepper slightly more than that. Refined piperine, by weight, is about one percent as hot as the capsaicin found in chili peppers. The outer fruit layer, left on black pepper, also contains aroma-contributing terpenes, including germacrene (11%), limonene (10%), pinene (10%), alpha-phellandrene (9%), and beta-caryophyllene (7%), which give citrusy, woody, and floral notes. These scents are mostly missing in white pepper, as the fermentation and other processing removes the fruit layer (which also contains some of the spicy piperine). Other flavours also commonly develop in this process, some of which are described as off-flavours when in excess: Primarily 3-methylindole (pig manure-like), 4-methylphenol (horse manure), 3-methylphenol (phenolic), and butyric acid (cheese).  The aroma of pepper is attributed to rotundone (3,4,5,6,7,8-Hexahydro-3α,8α-dimethyl-5α-(1-methylethenyl)azulene-1(2H)-one), a sesquiterpene originally discovered in the tubers of Cyperus rotundus, which can be detected in concentrations of 0.4 nanograms/l in water and in wine: rotundone is also present in marjoram, oregano, rosemary, basil, thyme, and geranium, as well as in some Shiraz wines.
Pepper loses flavour and aroma through evaporation, so airtight storage helps preserve its spiciness longer. Pepper can also lose flavour when exposed to light, which can transform piperine into nearly tasteless isochavicine. Once ground, pepper's aromatics can evaporate quickly; most culinary sources recommend grinding whole peppercorns immediately before use for this reason. Handheld pepper mills or grinders, which mechanically grind or crush whole peppercorns, are used for this as an alternative to pepper shakers that dispense ground pepper. Spice mills such as pepper mills were found in European kitchens as early as the 14th century, but the mortar and pestle used earlier for crushing pepper have remained a popular method for centuries, as well.
Enhancing the flavour profile of peppercorns (including piperine and essential oils), prior to processing, has been attempted through the postharvest application of ultraviolet-C light (UV-C).
Black pepper