Scoville Scale & Jalapeño Heat Levels
What Scoville heat units mean, where jalapeños rank on the scale, and how growing conditions affect pepper heat.
2,500-8,000
Jalapeño SHU
Mild-Med
Heat category
1912
Scoville scale invented
Quick Answer
Jalapeños measure 2,500-8,000 Scoville Heat Units (SHU), placing them in the mild-to-medium range. Heat varies based on growing stress, maturity, and genetics — stressed plants and riper (red) peppers tend to be hotter.
What Is the Scoville Scale?
The Scoville scale measures the pungency (heat) of chili peppers in Scoville Heat Units (SHU). It was developed in 1912 by pharmacist Wilbur Scoville using a panel of tasters to determine how much sugar water was needed to neutralize the heat. Today, heat is measured using high-performance liquid chromatography (HPLC), which detects capsaicin concentration and converts it to SHU. The result is more precise and reproducible.
Where Jalapeños Rank
- Bell Pepper:0 SHU
- Banana Pepper:0-500 SHU
- Poblano:1,000-1,500 SHU
- Jalapeño:2,500-8,000 SHU
- Serrano:10,000-23,000 SHU
- Cayenne:30,000-50,000 SHU
- Habanero:100,000-350,000 SHU
- Ghost Pepper:~1,000,000 SHU
- Carolina Reaper:1,600,000-2,200,000 SHU
Jalapeños sit in the mild-to-medium range, making them one of the most accessible hot peppers for cooking.
What Affects Jalapeño Heat
Several factors influence how hot a jalapeño will be:
Stress: Plants under mild stress (slightly less water, more sun) produce hotter peppers as a defense mechanism.
Maturity: Red (fully ripe) jalapeños are typically hotter than green ones.
Genetics: Some jalapeño cultivars are bred for more or less heat.
Seeds and pith: The white membrane (pith) inside the pepper contains the most capsaicin. Seeds themselves are not hot, but they are coated in capsaicin from contact with the pith.
Growing conditions: Hot, dry climates tend to produce hotter peppers than cool, wet ones.
Grow Hotter Peppers