Scoville heat units (SHU)

The Scoville scale is a measurement of the spicy heat (or piquance) of achili pepper.

The number of Scoville heat units (SHU)^[1] indicates the amount of capsaicin present. Capsaicin is a chemical compoundthat stimulateschemoreceptor nerve endings in the skin, especially the mucous membranes.

The scale is named after its creator, American chemist Wilbur Scoville. His method, devised in 1912,^[2] is known as the Scoville Organoleptic Test. An alternative method for quantitative analysis uses high-performance liquid chromatography, making it possible to directly measure capsaicinoid content.

Contents 1 Scoville organoleptic test 2 High-performance liquid chromatography 3 Hottest chilis 4 List of Scoville ratings 5 References

Scoville organoleptic test

In Scoville's method, an alcohol extract of the capsaicin oil from a measured amount of dried pepper is added incrementally to a solution of sugar in water until the "heat" is just detectable by a panel of (usually five) tasters; the degree of dilution gives its measure on the Scoville scale. Thus a sweet pepper or a bell pepper, containing no capsaicin at all, has a Scoville rating of zero, meaning no heat detectable. The hottest chilis, such as habaneros and nagas, have a rating of 200,000 or more, indicating that their extract must be diluted over 200,000 times before the capsaicin presence is undetectable. The greatest weakness of the Scoville Organoleptic Test is its imprecision, because it relies on human subjectivity. Tasters taste only one sample per session.

Naga Jolokia (bhut jolokia, naga morich) is rated at over one million Scoville units. It is primarily found in Bangladesh and the Northeast Indian states of Assam, Nagalandand Manipur The Red Savina pepper, one of the hottest chilis, is rated at 580,000 Scoville units.

Hottest chilis

The chilis with the highest rating on the Scoville scale exceed one million Scoville units and include specimens of naga jolokia or bhut jolokia and its cultivars, the "Dorset naga" and the "Ghost chili," neither of which has official cultivar status.^[4][5] Numerical results for any specimen vary depending on its cultivation conditions and the uncertainty of the laboratory methods used to assess the capsaicinoid content.

List of Scoville ratings

Pungency values for any pepper are variable, due to expected variation within a species—easily by a factor of 10 or more—depending on seed lineage, climate (humidity is a big factor for the Bhut Jolokia; the Dorset Naga and the original Naga have quite different ratings), and even soil (this is especially true of habaneros). The inaccuracies described in the measurement methods above also contribute to the imprecision of these values. When interpreting Scoville ratings, this should be kept in mind.^[3]

The Scoville scale may be extrapolated to express the pungency of substances that are even hotter than pure capsaicin. One such substance isresiniferatoxin, an alkaloid present in the sap of some species of euphorbiaplants (spurges), with a Scoville scale rating of 16 billion.^[6]

Scoville heat units	Examples
15,000,000–16,000,000	Pure capsaicin[7]
8,600,000–9,100,000	Various capsaicinoids (e.g., homocapsaicin,homodihydrocapsaicin, nordihydrocapsaicin)
5,000,000–5,300,000	Law Enforcement Grade pepper spray,[8] FN 303 irritant ammunition
855,000–1,075,000	Naga Jolokia (ghost chili)[9][10]
350,000–580,000	Red Savina habanero[11][12]
100,000–350,000	Guntur Chilli, Habanero chili,[13] Scotch Bonnet Pepper,[13] Datil pepper, Rocoto, African Birdseye (Piri Piri), Madame Jeanette, Jamaican Hot Pepper[14]
50,000–100,000	Bird's eye chili/Thai Pepper/Indian Pepper,[15]Malagueta Pepper,[15] Chiltepin Pepper, Pequin Pepper[15]
30,000–50,000	Cayenne Pepper, Ají pepper,[13] Tabasco pepper, Cumari pepper (Capsicum Chinese)
10,000–23,000	Serrano Pepper, Peter Pepper
2,500–8,000	Jalapeño Pepper, Guajillo pepper, New Mexican varieties of Anaheim pepper,[16] Paprika (Hungarian wax pepper), Tabasco Sauce
500–2,500	Anaheim pepper, Poblano Pepper, Rocotillo Pepper, Peppadew
100–500	Pimento, Peperoncini
0	No significant heat, Bell pepper, Cubanelle, Aji dulce