The strength of spice in a chili is measured with a scale known as the Scoville scale, which represents the quantity of the chemical, Capsaicin in a chili, as units of heat. This chemical is what creates the spiciness of the pepper by affecting the ends of the nerves in the skin. Like other scales, the Scoville scale was named after its founder. Wilbur Scoville created the test to gauge the amount of Capsaicin in peppers.
Scoville organoleptic test
The process of Scoville’s test involves an amount of capsaicin oil to sugar water. This is done periodically until the spice can only just be tasted by a panel of tasters. How diluted the oil is when it is tasted it represented on the scale in units. The higher the number of units, the spicier the pepper. A chili could be shown as having up to 200, 000 units of heat. The number of units shows how many times the capsaicin must be diluted until it can no longer be tasted. As the testing relies on an individual’s sense of taste, the test is subjective. If the test is subjective, it cannot be shown to be scientifically precise.
High-performance liquid chromatography
Chromatography is an alternative method of measuring the heat of a pepper. An empirical measurement is taken through a calculation of the weight of the item and its ability to create a sense of heat. The result is shown in terms of parts, so the greater number of parts of capsaicin per million, the hotter the pepper. This method generally gives a lower reading of spiciness compared to Scoville’s method of testing.
The hottest chili pepper could be represented on Scoville’s scale as exceeding a million units. How hot the pepper will be shown to be depends on where it was cultivated, but also how it is tested.
List of Scoville ratings
How strong a pepper is to taste will vary according to how it is cultivated, the climate in which it was grown, the soil it was grown in and how it is tested. Although it is a given that a pepper will naturally vary in taste according to environmental factors, the extent to which it will vary cannot be accurate gauged because of unreliable methods.
Although the methods described are used to measure the content of capsaicin, Scoville’s scale has been used to rate the pungency of the ‘hotter’ substance, ‘resiniferatoxin’. Resiniferatoxin is shown at 16 billion units.