How hot chiles are rated

How hot chiles are rated

Hot chiles range from mild hot to very hot. Hot chiles are rated by a scale known as the Scoville Scale.

By Katina Lewis

Hot chiles (or often spelled chilis) are not all created equal. Some have a very immediate spice and bite to them giving them the sensation that they are really hot or have a lot of heat as it is called. But others have a gently lingering bite that is mild and is easy to withstand.

Background on the Heat of a Chile

The amount of heat in hot chiles varies. This variance relates to the amount of capsaicin in each of the chiles. Capsaicin is the chemical that gives the chile its spice. It is alkaline (or basic) in nature and is made of many other smaller substances known as capsaicinoids.

Capsaicin itself has no odor or flavor. It is an oil so it is highly soluble in other oil and oil like substances. This means it will easily incorporate itself into foods that contain high amounts of fat and oils. It is only slightly water soluble meaning that it tends to stay separate from foods high in water content.

The substance affects directly pain receptors in the mouth and membrane linings on the nose and throat. It is believed that chiles evolved this substance as a weapon against predators. Capsaicin, in a concentrated form only made in laboratories, could easily leave damage to the mouth and tongue.

But with each pain receptor that is touched the brain immediately sends out substances to calm this feeling. Each time new chiles are eaten and capsaicin released into the system, the brain fires back the calming substances. This is why some have cravings for chiles. They become an addiction of sorts.


Chiles are rated by a scale known as the Scoville Scale. It is common to rate the chiles as Scoville Units or Scoville Heat Units. This scale measures the amount of capsaicin oil in each chile. The amount of oil directly correlates to the heat the chile has.

It is widely thought that the heat of the chile is in the seeds. While that is certainly true, the greatest amount of capsaicin is in the white membranes surrounding the seeds. To remove the heat from the chile, you would need to remove the membranes and the seeds. Exposure to the chiles seeds and membranes can lead to irritation of the skin so be careful when removing these. Most people remove these with gloves or a utensil in which they do not have to expose themselves directly to the chile.

Scoville Scale

The Scoville Scale was developed in 1912 by Wilbur Scoville. AT first it was only based on taste. But as science progressed so did the tests on chiles and the substances that made the chiles hot and spicy.

The first tests involved small amounts of the chile and usually a diluted solution of sugar water. Each of the testers would test the chile and see how much of the sugar water it took until the heat of the chile went away.

Today it is measured by special high-tech machines that use the chemical nature of the capsaicin to measure the units.

There are four general sections in the Scoville Scale ranging from mild to very hot.

Mild: 0-5,000 Scoville Units
Medium: 5,000-20,000 Scoville Units
Hot: 20,000-70,000 Scoville Units
Very Hot: 70,000-300,000 Scoville Units

The hottest recorded chile is the Red Savina Habenero registering at 577,000 Scoville Units, probably too hot for the general chile consumer. Pure Capsaicin that is made in laboratories registers sixteen million on the Scoville Scale.

Here is a listing of common chiles and their average Scoville Scale rating. These units are dependant on the cultivar or specific subtype of the chile thus the need for a wide range.

Poblano or Ancho: 1,000-3,000
Jalapeno: 2,000-4,000
Serrano: 7,000-25,000
Cayenne: 35,000
Thai: 70,000-80,000
Scotch Bonnet: 70,000-100,000
Habenero: 100,000-300,000
Red Savina Habenero: 577,000

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