What is the Scoville scale?

The Scoville scale is a standardized way of measuring the concentration of capsaicin, the compound that gives chili peppers their heat. Scoville heat units (SHU) are a measure of the spiciness or heat level of a chili pepper. Capsaicin is measured in parts per million (ppm), and the Scoville scale assigns a number to each pepper based on how many times the capsaicin concentration must be diluted before it is no longer detectable.

The scale ranges from 0 SHU (for a bell pepper, which has no capsaicin) to over 2 million SHU (for some of the hottest chili peppers). Here is a rough breakdown of the Scoville scale:

• 0-100 SHU: Bell peppers, sweet peppers, and pimentos
• 100-1,000 SHU: Poblano peppers, Anaheim peppers, and ancho peppers
• 1,000-5,000 SHU: Jalapeno peppers, serrano peppers, and cayenne peppers
• 5,000-30,000 SHU: Tabasco peppers, Thai peppers, and piri piri peppers
• 30,000-100,000 SHU: Habanero peppers, Scotch bonnet peppers, and bird's eye peppers
• 100,000-2,000,000 SHU: Carolina Reaper, Trinidad Scorpion, and Ghost pepper