What are Scoville Units?

(select this link to see an updated report on pepper seed heat levels by the Chile Pepper Institute)

A pharmacist named Wilbur Scoville invented the Scoville Scale in 1912 to measure the heat of peppers. A "Scoville Unit" is actually a measure of capsaicin (the chemical in hot peppers that is responsible for their heat).

Scoville's test was a comparative taste test that is considered subjective by today's standards. A more sophisticated method is in use today, but in honor of Wilbur Scoville, the unit of measure is still called the Scoville.

The capsaicin level in peppers can vary from plant to plant due to local environmental conditions. This means that a pepper's rating is an average measure.

The hottest pepper on record is, depending where you read the latest 'hottest find', either the Naga Jolokia, Dorset Naga, or Bhut Jolokia.  All are relatively recent finds with claims up to 1 million scoville units.  By contrast, the Serrano Pepper comes in at about 5,000 to 15,000 Scoville units.

Scoville Units Pepper Pepper Pepper
300,000 to 1,000,000 Naga Jolokia Dorset Naga Bhut Jolokia
100,000 to 300,000 Habanero Red Savina  
50,000 to 100,000 Chile tepin Thai  
30,000 to 50,000 Tabasco Pequin Cayenne
15,000 to 30,000 De Arbol    
5,000 to 15,000 Serrano    
2,500 to 5,000 Guajillo Jalapeno Mirasol
1,500 to 2,500 Rocotillo Cascabel  
1,000 to 1,500 Negro Ancho Pasilla
500 to 1,000 New Mexico Anaheim Mulato
100 to 500 Cherry    
Zero Bell Pimento