Ever wonder just how hot a chili pepper or sauce actually is? Well, there just so happens to be a scale that measures that. This is of course common knowledge among chiliheads, but the average mortal may not have heard of the handy, dandy system known as the Scoville Scale.
Created in 1912 by an American pharmacist named Wilbur Scoville, this scale measures the pungency of chili peppers based on a measurement known as Scoville Heat Units (SHU) and it relates to the parts per million needed to dilute the heat in water (gonna need a pretty big glass of aqua for the habaneros and more!). Now, if you want to get into all the fancy science of how the measurement works, I’ll direct you to the Wikipedia page to start, and then you can work your way into all sorts of book learning from there. But for us simple folks, the Scoville Scale just tells us if a chili pepper, hot sauce, or some other spicy item is hot or not!
Following are the levels of pungency that were originally used for the scale:
| Pungency | SHU |
| Very highly pungent | Above 80,000 |
| Highly pungent | 25,000 to 70,000 |
| Moderately pungent | 3,000 to 25,000 |
| Mildly pungent | 700 to 3,000 |
| Non pungent | 0 to 700 |
A bell pepper sets the baseline at 0 Scoville Heat Units in the Non Pungent category. Poblanos and New Mexico Green Chilis typically run around 1,000 to 3,000 SHU, though they can be hotter. Jalapenos typically run around 2,500 to 10,000 SHU and the serrano kicks that up to between 10,000 and 25,000 SHU. The cayenne and Tabasco pepper range from 25,000 to 50,000 SHU. And topping out the original pungency levels are peppers like the Thai chili, the chiltepin, and the pequin, coming in between 50,000 and 100,000 SHU.
These days, there are many more chilis from around the world that have become popular and have pushed up the heat levels. The habanero and scotch bonnet range from 100,000 to 350,000 SHU. The Red Savina habanero ramps that up to 350,000-750,000 SHU, while the Trinidad Scorpion chili and the ghost pepper push pass the million SHU mark coming in between 750,000 and 1,500,000. The Carolina Reaper reaches for the top of the scale, going as high as three million Scoville Units. That’s about where stand police pepper spray starts by the way!
There are hotter chilis out there, but even some of your most dedicated chiliheads will have trouble tackling those! Wikipedia provides a scale that covers most of your commonly found chilis (and some that are not so common) that should act as a good reference point. And I will be adding a customized chart to this site in the coming weeks.