The Scoville scale is a measurement of the pungency (spicy heat) of chili peppers—or other spicy foods as reported in Scoville heat units (SHU), a function of capsaicin concentration. Capsaicin is one of many related chemicals, collectively called capsaicinoids. The scale is named after its creator, American pharmacist Wilbur Scoville. His method, devised in 1912, is known as the Scoville Organoleptic Test.
Unlike methods based on high-performance liquid chromatography, the Scoville scale is a subjective measurement dependent on the capsaicin sensitivity of testers and so is not a precise or accurate method to measure capsaicinoid concentration.
Scoville organoleptic test
In Scoville's method, an exact weight of dried pepper is dissolved in alcohol to extract the heat components (capsaicinoids), then diluted in a solution of sugar water. Decreasing concentrations of the extracted capsinoids are given to a panel of five trained tasters, until a majority (at least three) can no longer detect the heat in a dilution. The heat level is based on this dilution, rated in multiples of 100 SHU.
A weakness of the Scoville Organoleptic Test is its imprecision due to human subjectivity, depending on the taster's palate and their number of mouth heat receptors, which varies greatly among people. Another weakness is sensory fatigue: the palate is quickly desensitised to capsaicins after tasting a few samples within a short time period. Results vary widely (up to ± 50%) between laboratories.
Since Scoville ratings are defined per unit of dry mass, comparison of ratings between products having different water content can be misleading. For example, typical fresh chili peppers have a water content around 90 percent, whereas Tabasco sauce has a water content of 95 percent. For law-enforcement-grade pepper spray, values from 500,000 up to 1 million SHU have been mentioned, but the actual strength of the spray depends on the dilution, which could vary by a factor of 10.
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 cultivar, the "ghost chili", which does not have official cultivar status. The Carolina Reaper is currently the highest rated pepper in the world.
Numerical results for any specimen vary depending on its cultivation conditions and the uncertainty of the laboratory methods used to assess the capsaicinoid content. Pungency values for any pepper are variable, owing 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.
|Scoville heat units||Examples|
ASTA pungency units
Since at least the 1980s, spice heat has been more precisely measured by a method that uses high-performance liquid chromatography (HPLC). This identifies and measures the concentration of heat-producing chemicals. The measurements are used in a mathematical formula that weights them according to their relative capacity to produce a sensation of heat. This method yields results, not in Scoville units, but in American Spice Trade Association (ASTA) pungency units. A measurement of one part capsaicin per million corresponds to about 16 Scoville units, and the published method says that ASTA pungency units can be multiplied by 16 and reported as Scoville units. Scoville units are a measure for capsaicin content per unit of dry mass.
- Peter, KV, ed. (2001), Handbook of Herbs and Spices, 1, CRC Press, p. 120, ISBN 0-8493-1217-5
- Scoville, Wilbur (May 1912). "Note on capsicums". Journal of the American Pharmaceutical Association. 1 (5): 453–4. doi:10.1002/jps.3080010520.
- Kleiman, Dena (November 8, 1989). "Rating Hot Peppers: Mouth vs. Computer". The New York Times. Retrieved 2014-11-02.
- Peter, K. V. (2012). Handbook of Herbs and Spices. Elsevier Science. p. 127. ISBN 978-0-85709-5671.
- Tainter, Donna R.; Anthony T. Grenis (2001). Spices and Seasonings. Wiley-IEEE. p. 30. ISBN 0-471-35575-5.
Interlab variation [for the original Scoville scale] could be as high as +/−50%. However, labs that run these procedures could generate reasonably repeatable results.
- Barry-Jester, Anna Maria (October 15, 2014). "Rating Chili Peppers On A Scale Of 1 To Oh Dear God I’m On Fire". FiveThirtyEight. Retrieved 2014-11-02.
- USDA nutrient database for Peppers, jalapeño, raw (92% water content); Peppers, hot chile, red, raw (88% water content); Red Tabasco sauce (95%)
- "Chemical hazards in law enforcement". The Police Policy Studies Council. Retrieved 2009-02-09.
Most law enforcement sprays have a pungency of 500,000 to 2 million SHU. One brand has sprays with 5.3 million SHU.
- "The Truth About Defensive Spray Heat". Sabre red.
Sabre Red = 10% OC @ 2,000,000 Scoville Heat Units. Thus, 90% of the formulation dilutes the 2,000,000 SHUs creating a Scoville Content of 200,000.
- "World’s hottest chilli grown in Grantham, Lincs". The Daily Telegraph. London. 2010-04-01. Retrieved 2010-04-24.
- "Grantham firm grows world's hottest chilli". UK: This is Lincolnshire. Retrieved 2010-04-24.
- "Hottest chili". Guinness World Records. Retrieved July 11, 2014.
- Hallock, Betty (December 26, 2013). "World's hottest pepper hits 2.2 million Scoville heat units". Los Angeles Times.
- "There’s A New World’s Hottest Chili And It’s So Spicy It Could Actually Kill You".
- Smithers, Rebecca (11 August 2015). "UK's hottest ever commercially grown chilli pepper to go on sale". The Guardian. Retrieved 15 August 2015.
- "Chile experts identify Trinidad Moruga Scorpion as world's hottest". The Daily Telegraph. UK. 2012-02-16.
- Dykes, Brett Michael (3 December 2010). "World’s hottest pepper is 'hot enough to strip paint'". Yahoo! News. Retrieved 3 December 2010.
- "Tezpur/Naga Jolokia – The Hottest Chile?" (PDF). The Chile Pepper Institute Newsletter. 11 (2). The Chile Pepper Institute, New Mexico State University. 2000. p. 5.
...the Red Savina Habanero whose Scoville rating is around 555,000 Scoville Heat Units (SHU), the 'Naga Jolokia' possesses 855,000 SHU.
- "Grantham's Infinity chilli named hottest in world". BBC News. 2011-02-18.
- Shaline L. Lopez (2007). "NMSU is home to the world's hottest chile pepper". Archived from the original on 2007-02-19. Retrieved 2007-02-21.
- "World's hottest chili pepper a mouthful for prof". CNN. AP. 23 February 2007. Archived from the original on 22 March 2007.
- Matthew Da Silva (12 April 2011). "World's hottest chilli grown by Aussies". Australian Geographic. Retrieved 22 January 2016.
- "UK's hottest commercially grown chilli pepper goes on sale". Tesco PLC. 10 September 2012. Retrieved 22 January 2016.
- Tom Ryan. "The Official Scoville Scale - Pepperheads For Life". Pepperheads For Life.
- "World's hottest chile pepper discovered". American Society for Horticultural Science. 2007-10-27. Retrieved 2008-03-31.
- "Burning Questions" (PDF). The Chile Pepper Institute Newsletter. 13 (3). The Chile Pepper Institute, New Mexico State University. 2002. p. 7.
...'Red Savina' habanero...came in at a whopping 577,000 Scoville Heat Units.
- "The Scoville Scale". HappyStove.com.
- "Habanero White". The Chile Man. Retrieved 2011-09-21.
- Scoville Food Institute, Periodic Table of Scoville Units.
- "The Scoville Scale". The Scoville Scale For Peppers.
- "Scoville Scale Chart for Hot Sauce and Hot Peppers". Scott Roberts. Retrieved 2008-11-19.
- Julius, David; Caterina, Michael J.; Schumacher, Mark A.; Tominaga, Makoto; Rosen, Tobias A.; Levine, Jon D. (1997). "The capsaicin receptor: a heat-activated ion channel in the pain pathway". Nature. 389 (6653): 816–824. ISSN 0028-0836. PMID 9349813. doi:10.1038/39807.
Reported pungencies for pepper varieties (in Scoville units) are: Habanero (H),100,000–300,000; Thai green (T), 50,000–100,000; wax (W), 5,000–10,000; and Poblano verde (P), 1,000–1,500 (ref. 23).
- Lillywhite, Jay M.; Simonsen, Jennifer E.; Uchanski, Mark E. (2013). "Spicy Pepper Consumption and Preferences in the United States". HortTechnology. 23 (6): 868–876.
Any pepper type with ≥ 1 SHU could be considered spicy. However, for this study, paprika (0–300 SHU), New Mexico long green or red chile (300–500 SHU), and poblano/ancho (≈1369 SHU) types were included as mild spicy peppers (Table 1).
- Thomas DeBaggio, Thomas DeBaggio; Arthur O. Tucker, Arthur O. Tucker (2009). The Encyclopedia of Herbs: A Comprehensive Reference to Herbs of Flavor and Fragrance. Timber Press. p. 188. ISBN 978-1-60469-134-4.
...a bell pepper has 0 Scoville Heat Units and a rating of 0.
- Laratta, B; De Masi, L; Sarli, G; Pignone, D (2013). Lanteri, Sergo; Rotino, Giuseppe Leonardo, eds. "Hot Peppers for Happiness and Wellness: a Rich Source of Healthy and Biologically Active Compounds" (PDF). Breakthroughs in the Genetics and Breeding of Capsicum and Eggplant: Proceedings of the XV EUCARPIA Meeting on Genetics and Breeding of Capsicum and Eggplant. Comitato per l'organizzazione degli eventi (COE) DISAFA, Università degli Studi di Torino: 233–240. ISBN 978-88-97239-16-1.
Scoville Heat Units (SHU), Referring pepper varieties...0, Sweet Bell
- DeWitt, Dave; Bosland, Paul W. (2009). The Complete Chile Pepper Book. ISBN 978-0-88192-920-1.
- Collins, M.D.; et al. (1995). "Improved Method for Quantifying Capsaicinoids in Capsicum Using High-performance Liquid Chromatography". HortScience. 30: 137–139.
- Nwokem, C.O.; et al. (2010). "Determination of Capsaicin Content and Pungency Level of Five Different Peppers Grown in Nigeria" (PDF). New York Science Journal. 3: 9.
- Othman, Z.A. Al; et al. (2011). "Determination of Capsaicin and Dihydrocapsaicin in Capsicum Fruit Samples using High Performance Liquid Chromatography". Molecules. 16 (12): 8919–8929. doi:10.3390/molecules16108919.