You may have seen labels on bottles of hot sauces or wrappers on hot chili products notifying the Scoville Heat Units (SHU) of the product. It’s an indicator of how hot is that chili product.
This article is a detailed guide to the Scoville Scale, its history, and how are the various hot peppers ranked.
What Is the Scoville Scale?
The Scoville scale is the standard testing system for measuring the level of spiciness or heat produced by hot peppers. Capsaicin, a phenolic compound found in chili peppers, is responsible for their characteristic taste and pungency. This scale measures the amount of capsaicin in chili peppers and assigns it a number rating in the Scoville Heat Units (SHUs).
The Scoville Scale is used for measuring the heat of anything that contains capsaicin; not only chili peppers but also anything made from chili peppers like hot sauce, pickles, or chili paste.
It actually measures the concentration of capsaicin in a chili. Capsaicin occurs naturally in peppers along with other capsaiciniods, the natural chemicals that give flavor and pungency to peppers.
Origin of Scoville Scale
The Scoville Scale and Scoville Heat Unit (SHU) were named for scientist Wilbur Scoville in 1912. While he was working at Parke-Davis, a pharmaceutical company, he invented a testing scale called the “Scoville Organoleptic Test”. It’s a subjective assessment derived from the capsaicinoid sensitivity people experience while eating hot chilies. The Scoville Scale Unit is the first standard testing mechanism for measuring the heat or pungency of chili pepper.
The Methodology of Scoville Testing
At the preliminary stages of developing the scale, Scoville would ground up the pepper and mix it with sugar and water, and then a panel of tasters who sipped from these pepper-sugar-water solutions. The guiding principle is how many equal parts of sugar water are required to be added to an equal measure of ground chili pepper until no discernible heat is tasted.
The solution was diluted by Scoville bit by bit until the tasters could no longer sense any heat from it. He assigned a number to the tested chili pepper based on the number of dilutions done to reach zero heat level.
The measurements are divided into multiple of 100. One part per 1,000,000 dilutions of water is rated at 1.5 Scoville Units. On this scale, pure capsaicin is rated between 15 – 16,000,000 SHU.
It is a strenuous lengthy task for the panel of tasters who took the test. They had to carry out several rounds of tasting the concoctions of pepper, sugar, and water, and this process would take several days of tasting until no heat was noticed per pepper type.
The numbers in Scoville Units represent the number of dilutions it took to get no-heat statues for chili pepper. For example, one teaspoon of ground cayenne pepper (30,000 to 50,000 SHU) would take approximately 30,000 to 50,000 teaspoons of sugar-water diluted bit by bit amount to achieve not an iota of spiciness felt in the mouth of tasters.
Merits and Demerits of the Scoville Scale
The measurement of hot chili peppers with the Scoville Scale is a very subjective test. There are factors that affect the findings and the result often varies among different laboratories.
The Scoville Organoleptic Test totally relies on the variability in people’s taste buds. Every individual differs in the amount of spiciness he or she can take, the results of the tasting would vary from tester to tester.
The very same type of peppers grown in different geographical conditions can have a vast difference in their spiciness and flavor. That is to say, the heat of a pepper largely depends on the growing conditions like soil, climate, use of manures, and availability of sunlight and water.
Recently developed High-Performance Liquid Chromatography (HPLC) tests can also be faulty especially because of the confusion surrounding their conversion into Scoville Heat Units. The conversion tends to position the heat of the peppers on the pepper scale very mildly compared to what a human tester would give.
In short, every method of measuring chili peppers won’t be accurate for the heat varies even in the same type of pepper, and the Scoville Scale is accurate enough to serve our purpose. This measuring scale helps to determine the heat of all sorts of foods that contain capsaicin.
Alternative to Scoville Scale
It’s a strenuous and time-consuming job for a panel of tasters to physically verify and decide the Scoville heat levels of each and every type of chili pepper and other chili-based products.
The ChilliPot is the world’s first Scoville Meter designed to quickly find out the Scoville Units of any chili pepper. This testing device is based on technology developed by the University of Oxford in 2007.
Another refined measuring unit is the Dremann Pepper Hotness Scale (DHS) which was developed in 1984 by Craig C. Dremann of the Redwood City Seed Co., California. It measures how many ounces of salsa will have a detectable level of heat when one ounce of pepper pods is added.
Today, analyzing and testing chili pepper heat is not so subjective. Scoville Scale is gradually being replaced by more efficient High-Performance Liquid Chromatography, or HPLC, which measures the pungency-producing chemicals in pepper and rates them in ASTA pungency units.
Scoville Scale For Chili Peppers
Here is the list of Scoville Heat Units (SHUs) of peppers from different parts of the world:
| Chili Pepper | Scoville Heat Units | Scoville Heat Level |
|---|---|---|
| Carolina Reaper (HP22B, Smokin' Ed's Carolina Reaper) | 1,500,000 - 2,200,000 SHU | 10+++ |
| Trinidad Moruga Scorpion (Moruga, Moruga Scorpion, Trinidad Moruga Scorpion Red) | 1,500,000 - 2,009,231 SHU | 10+++ |
| Chocolate 7 Pot (7 Pot Douglah) | 1,000,000 - 1,853,936 SHU | 10+++ |
| Katie (7 Pot Katie) | 1,200,000 - 1,590,000 SHU | 10+++ |
| Trinidad 7 Pot Primo (Primo, 7 Pot Primo) | 1,100,000 - 1,469,000 SHU | 10++ |
| Butch T (Trinidad Scorpion Butch Taylor) | 800,000 - 1,463,700 SHU | 10++ |
| Komodo Dragon (British Komodo Dragon) | 500,000 - 1,400,000 SHU | 10++ |
| Trinidad Red Scorpion (Trinidad Scorpion, Scorpion Pepper) | 500,000 - 1,390,000 SHU | 10++ |
| Naga Viper | 600,000 - 1,382,118 SHU | 10++ |
| Lucy (7 Pot Lucy) | 900,000 - 1,359,284 SHU | 10++ |
| 7 Pot Barrackpore | 900,000 - 1,300,000 SHU | 10++ |
| 7 Pot Jonah | 800,000 - 1,200,000 SHU | 10+ |
| Brain Strain (7 Pot Brain Strain) | 800,000 - 1,200,000 SHU | 10+ |
| Yellow Brain Strain (7 Pot Brain Strain Yellow) | 700,000 - 1,200,000 SHU | 10+ |
| New Mexico Scorpion | 500,000 - 1,191,595 SHU | 10+ |
| Bedfordshire Super Naga | 500,000 - 1,120,000 SHU | 10+ |
| 7 Pot | 500,000 - 1,100,000 SHU | 10+ |
| Spanish Naga (Naga Gibraltar) | 600,000 - 1,086,844 SHU | 10+ |
| Infinity Chili (Infinity Pepper) | 500,000 - 1,067,286 SHU | 10+ |
| 7 Pot Madballz (Madballz Pepper) | 750,000 - 1,066,882 SHU | 10+ |
| Bhut Jolokia, Ghost Pepper (Bih Jolokia, Naga Jolokia, Ghost, Geisterchili, Red Naga, U-morok, Bombai Morich, Raja Mirch, Saga Jolokia, Indian Mystery Chili, Indian Rough Chili , Tezpur Chili) | 600,000 - 1,041,427 SHU | 10+ |
| Bhut Jolokia Chocolate (Naga Jolokia Chocolate, Chocolate Ghost Pepper, Brown Naga) | 500,000 - 1,001,300 SHU | 10+ |
| 7 Pot Armageddon (Armageddon) | 855,000 - 1,000,000 SHU | 10+ |
| 7 Pot Bubblegum (Bubblegum, 7 Pot BBG) | 840,000 - 1,000,000 SHU | 10+ |
| 7 Pot White (White Seven Pot) | 800,000 - 1,000,000 SHU | 10+ |
| Trinidad Orange Scorpion (Orange Trinidad, Trinidad Scorpion Orange) | 700,000 - 1,000,000 SHU | 10+ |
| Naga Morich (Dorset Naga) | 600,000 - 1,000,000 SHU | 10+ |
| Raja Mirch (Synonym for Bhut Jolokia, SHU measurement from India) | 450,000 - 900,000 SHU | 10+ |
| Trinidad 7 Pot Cardi (7 Pot Cardi, CARDI) | 500,000 - 850,000 SHU | 10+ |
| 7 Pot Yellow (Trinidad 7 Pot Yellow) | 450,000 - 600,000 SHU | 10 |
| Trinidad Yellow Scorpion | 400,000 - 600,000 SHU | 10 |
| Red Savina (Habanero Red Savina) | 250,000 - 577,000 SHU | 10 |
| Devil's Tongue Chocolate (Brown Devil's Tongue) | 400,000 - 500,000 SHU | 10 |
| Devil's Tongue Red | 350,000 - 500,000 SHU | 10 |
| Habanero Francisca (Habanero Francisca Orange) | 300,000 - 500,000 SHU | 10 |
| Habanero Chocolate (Brown Habanero) | 300,000 - 500,000 SHU | 10 |
| Fatalii Peach (Peach Fatalii) | 150,000 - 500,000 SHU | 10 |
| Fatalii White (White Fatalii) | 150,000 - 500,000 SHU | 10 |
| Fatalii Yellow (Yellow Fatalii) | 125,000 - 500,000 SHU | 10 |
| Adjuma (Aji Umba, Adjoema, Ojemma) | 100,000 - 500,000 SHU | 10 |
| Fatalii Red (Red Fatalii) | 100,000 - 500,000 SHU | 10 |
| Black Congo Pepper | 300,000 - 450,000 SHU | 10 |
| Caribbean Red | 300,000 - 445,000 SHU | 10 |
| Devil's Tongue Yellow | 300,000 - 400,000 SHU | 10 |
| Hot Paper Lantern | 300,000 - 400,000 SHU | 10 |
| Habanero Golden | 300,000 - 400,000 SHU | 10 |
| Habanero White Bullet | 300,000 - 400,000 SHU | 10 |
| Red Congo Pepper | 250,000 - 400,000 SHU | 10 |
| Habanero Red (Red Habanero) | 150,000 - 350,000 SHU | 10 |
| Madame Jeanette (Suriname Yellow) | 150,000 - 350,000 SHU | 10 |
| Habanero Orange | 100,000 - 350,000 SHU | 10 |
| Habanero Peach | 100,000 - 350,000 SHU | 10 |
| Habanero Mustard | 100,000 - 350,000 SHU | 10 |
| Habanero White | 100,000 - 350,000 SHU | 10 |
| Tiger Paw (Tiger Paw Habanero, Orange Tiger Paw) | 200,000 - 330,000 SHU | 10 |
| Scotch Bonnet Red | 150,000 - 325,000 SHU | 10 |
| Habanero Big Sun | 150,000 - 325,000 SHU | 10 |
| Burkina Yellow (Habanero Burkina Yellow, Burkina Scotch Bonnet) | 100,000 - 325,000 SHU | 10 |
| Habanero Yellow (Gelbe Habanero) | 130,000 - 310,000 SHU | 10 |
| Habanero Orange Devil | 200,000 - 300,000 SHU | 10 |
| Habanero Peruvian White | 200,000 - 300,000 SHU | 10 |
| Scotch Bonnet Orange | 125,000 - 300,000 SHU | 10 |
| Scotch Bonnet Yellow | 125,000 - 300,000 SHU | 10 |
| Yellow Congo Pepper | 150,000 - 300,000 SHU | 10 |
| Bahamian Goat Pepper (Bahamian Pepper) | 100,000 - 300,000 SHU | 10 |
| Datil (Datil Pepper) | 100,000 - 300,000 SHU | 10 |
| Billy Goat | 100,000 - 300,000 SHU | 10 |
| Jamaican Hot Red (Red Jamaican Hot Pepper) | 100,000 - 250,000 SHU | 10 |
| Scarlet Lantern (Peru Scarlet Lantern) | 50,000 - 250,000 SHU | 9 |
| Pimenta de Neyde (Pimenta da Neyde) | 50,000 - 250,000 SHU | 9 |
| Jamaican Hot Yellow | 100,000 - 225,000 SHU | 9 |
| Bird's Eye (Bird Pepper, Bird Eye Chili) (Note: the name is used for several bird pepper varieties) | 100,000 - 225,000 SHU | 9 |
| Carolina Cayenne Red (Carolina Cayenne Pepper) | 80,000 - 125,000 SHU | 9 |
| Tabiche Pepper | 50,000 - 110,000 SHU | 9 |
| Basket of Fire | 80,000 - 100,000 SHU | 9 |
| Pico De Pajaro (Cola de Rata, Rat's Tail, Bird's Peak) | 70,000 - 100,000 SHU | 9 |
| Charleston Hot (Charleston Hot Red, Charleston Hot Cayenne) | 70,000 - 100,000 SHU | 9 |
| Diablo Grande Pepper | 60,000 - 100,000 SHU | 9 |
| Yellow Bumpy | 50,000 - 100,000 SHU | 9 |
| Chupetinha | 50,000 - 100,000 SHU | 9 |
| Aji Limo | 50,000 - 100,000 SHU | 9 |
| Indian PC-1 | 50,000 - 100,000 SHU | 9 |
| Thai Chili (Note: the name is used for several Thai pepper varieties) | 50,000 - 100,000 SHU | 9 |
| Tepin (Chiltepin, Chiltecpin, Chil Tepin) | 50,000 - 100,000 SHU | 9 |
| Pequin (Piquin, Pee-keen) | 50,000 - 100,000 SHU | 9 |
| Malagueta (Mala, Malaguetinha) | 60,000 - 90,000 SHU | 8 |
| Diablo Grande | 50,000 - 90,000 SHU | 8 |
| Thai Dragon | 35,000 - 90,000 SHU | 8 |
| Tien Tsin | 45,000 - 75,000 SHU | 8 |
| Rocoto Peron (Rocoto Peron Rojo, Red Tree Pepper) | 30,000 - 75,000 SHU | 8 |
| Rocoto Rojo (Aji Rojo, Red Tree Pepper) | 30,000 - 75,000 SHU | 8 |
| Rocoto Amarillo (Rocoto Manzano Amarillo, Chile Manzano Amarillo, Aji Amarillo, Tree Pepper) | 30,000 - 75,000 SHU | 8 |
| Rocoto Canario (Locoto Canario, Yellow Rocoto, Yellow Tree Pepper) | 30,000 - 75,000 SHU | 8 |
| Rocoto de Seda (De Seda, Chile de Seda, Tree Pepper) | 30,000 - 75,000 SHU | 8 |
| Bangalore Whippet's Tail | 30,000 - 60,000 SHU | 7 |
| Jalapeño NuMex Pinata (NuMex Pinata) | 40,000 - 50,000 SHU | 7 |
| Maraba | 30,000 - 50,000 SHU | 7 |
| Aji Charapita | 30,000 - 50,000 SHU | 7 |
| Capsicum Eximium | 30,000 - 50,000 SHU | 7 |
| Rocoto Manzano (Chile Manzano) | 30,000 - 50,000 SHU | 7 |
| Cayenne (Red Cayenne, De Cayenna) | 30,000 - 50,000 SHU | 7 |
| Santaka | 30,000 - 50,000 SHU | 7 |
| Prik Kee Nu (Prik Kee Noo, พริกขี้หนู "Mäusekot Chili") | 30,000 - 50,000 SHU | 7 |
| Tabasco (Greenleaf Tabasco) | 30,000 - 50,000 SHU | 7 |
| Pimenta de Cheiro (Note: the name is used for several Brazilian pepper varieties) | 20,000 - 50,000 SHU | 7 |
| Lemon Drop (Hot Lemon, Aji Limon, Aji Lemon) | 15,000 - 30,000 SHU | 6 |
| Aji Colorado | 15,000 - 30,000 SHU | 6 |
| Aji Pineapple | 15,000 - 30,000 SHU | 6 |
| Criola Sella | 15,000 - 30,000 SHU | 6 |
| Mushroom Red (Red Mushroom Pepper) | 15,000 - 30,000 SHU | 6 |
| De Arbol (Chile de Arbol, De árbol, Spanish Tree Pepper) | 15,000 - 30,000 SHU | 6 |
| Royal Black | 5,000 - 30,000 SHU | 6 |
| Maule's Red Hot (Maule's Red, Lady Finger) | 5,000 - 30,000 SHU | 6 |
| Serrano | 10,000 - 25,000 SHU | 6 |
| Chungyang Red (Red Chungyang Pepper) | 10,000 - 25,000 SHU | 6 |
| Bishop's Crown (Bishops Crown) | 5,000 - 15,000 SHU | 5 |
| Chipotle (Smoked Jalapeño, Roasted Jalapeño Peppers) | 5,000 - 10,000 SHU | 5 |
| Hungarian Hot Wax (Hot Wax, Wax Pepper) | 5,000 - 10,000 SHU | 5 |
| Aleppo (Halaby pepper, Aleppo Pepper, Pul Biber, Fulful Ḥalabī) | 5,000 - 10,000 SHU | 5 |
| Fresno | 2,500 - 10,000 SHU | 5 |
| Jalapeño | 2,500 - 8,000 SHU | 5 |
| Jalapeño Deep Purple (Purple Jalapeño) | 2,000 - 8,000 SHU | 5 |
| Jalapeño Early | 4,000 - 6,000 SHU | 5 |
| Guajillo (Guajillo Pepper, Mexican Guajillo, Guajilla) | 2,500 - 5,000 SHU | 4 |
| NuMex Mirasol (Mirasol) | 2,500 - 5,000 SHU | 4 |
| Hot Cherry Pepper (Cherry Pepper, Hot Cherry Pepper, Hungarian Cherry Pepper, Hungarian Cherry) | 2,500 - 5,000 SHU | 4 |
| Candlelight | 1,000 - 5,000 SHU | 4 |
| Ancho San Luis (Mexican Large) | 1,500 - 4,000 SHU | 4 |
| Cherry Bomb (Cherry Bomb Pepper) | 1,000 - 3,000 SHU | 3 |
| NuMex Sandia (Sandia Pepper) | 1,500 - 2,500 SHU | 3 |
| Cascabel (Rattle Pepper, Mexican Cascabel Pepper) | 1,500 - 2,500 SHU | 3 |
| Anaheim (Magdalena, California Chile, Chile Seco Del Norte, New Mexico Chile Pepper Cultivar No, 9) | 500 - 2,500 SHU | 3 |
| NuMex Big Jim (Big Jim, NuMex Heritage Big Jim) | 500 - 2,500 SHU | 3 |
| Poblano (Ancho Pepper, Ancho Poblano) | 1,000 - 2,000 SHU | 2 |
| Pasilla (Pasilla Pepper, Chilaca, Chile Negro) | 1,000 - 2,000 SHU | 2 |
| Alma Pepper (Alma Csipös) | 1,000 - 1,500 SHU | 2 |
| Espanola (New Mexico Espanola Pepper) | 1,000 – 1,500 | 2 |
| Vulcano | 700 - 1,500 SHU | 2 |
| Peppadew | 1,000 - 1,200 SHU | 2 |
| Coronado | 700 - 1,000 SHU | 1 |
| NuMex Sunrise | 500 - 1,000 SHU | 1 |
| NuMex Conquistador | 500 - 1,000 SHU | 1 |
| Cubanelle Pepper | 100 - 1,000 SHU | 1 |
| NuMex Joe E, Parker | 500 - 1,000 SHU | 1 |
| Golden Greek (Golden Greek Peperoncino, Greek Peperoni) | 0 - 1,000 SHU | 1 |
| NuMex Suave Red | 500 - 850 SHU | 1 |
| NuMex Suave Orange | 500 - 830 SHU | 1 |
| Santa Fe Grande (Guero Chili Pepper) | 500 - 750 SHU | 1 |
| Aji Dulce Amarillo | 100 - 500 SHU | 1 |
| Aji Dulce (Aji Cachucha, Ajicito, Ají Gustoso) | 100 - 500 SHU | 1 |
| Pepperoncini (Peperoncino, Italian Sweet Pepper, Tuscan Pepper) | 100 - 500 SHU | 1 |
| Trinidad Perfume | 0 - 500 SHU | 1 |
| Gorria (Piment d'Espelette, Ezpeletako Biperra, Biper) | 0 - 500 SHU | 1 |
| Lombardo (Lombardo Peperoni) | 0 - 500 SHU | 1 |
| Friggitello (Friggitelli, Italian Piemento, Sweet Italian Pepper) | 0 - 500 SHU | 1 |
| Shishito (Shishitōgarashi, Japanese Pimiento, Shishito Pepper) | 50 - 200 SHU | 1 |
| Capsicum Rhomboideum (Former: Capsicum Cilliatum, Witheringia Ciliata) | 0 SHU | 0 |
| Minibell Chocolate (Minibell Brown, Brown Snack Pepper) | 0 SHU | 0 |
| Minibell Orange (Orange Snack Pepper) | 0 SHU | 0 |
| Minibell Red (Red Snack Pepper) | 0 SHU | 0 |
| Sweet Sunshine (Sweet Sunshine Trailing Pepper) | 0 SHU | 0 |
| Süßer Naschzipfel | 0 SHU | 0 |
| Corno di Toro Rosso | 0 SHU | 0 |
| Corno di Toro Giallo | 0 SHU | 0 |
| California Wonder | 0 SHU | 0 |
| Yolo Wonder | 0 SHU | 0 |
| Bell Pepper | 0 SHU | 0 |