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The Heat of Chili Peppers is measured by Scoville Heat Units (SHUs) – What's that?

What is the Scoville Scale and Scoville Heat Units

The Scoville Scale and Scoville Heat Unit (SHU) were named for scientist Wilbur Scoville (1/22/1865 in Bridgeport, CT- 3/10/1942 in Gainesville, FL) in 1912. At the time, Scoville worked for a pharmaceutical company named Parke-Davis where he developed a test called the “Scoville Organoleptic Test” which is used to measure various chili pepper’s pungency, spiciness and heat.

Originally, Scoville ground up peppers and mixed them with sugar water, then tested them with a panel of tasters who sipped from these sugar-water-pepper solutions.

He would then dilute the solutions bit by bit until they no longer burned the tongues of the tasters, after which he would assign a number to the chile pepper based on the number of dilutions needed to kill the heat.

For parts per million (ppm) measurements, SHU units are calculated from "parts per million of heat" (ppmH), which is found as following. The measurements are divided into multiples of 100. Note that 1 part per 1,000,000 dilutions of water is rated at 1.5 Scoville Units. Pure capsaicin, the stuff that makes chili peppers hot, is rated between 15 – 16,000,000 Scoville heat units.

Alternatively, since the 1980s, spice heat has been assessed quantitatively by high-performance liquid chromatography (HPLC), which measures the concentration of heat-producing capsaicin, typically with capsaicin content as the main measure. It is used to analytically quantify the capsaicin content as an indicator of pungency. As of 2011, the original subjective organoleptic test has been largely superseded by analytical methods such as HPLC.

The rare Aji Charapita Pepper we are growing at Charapita Farms ( has between 30,000 and 50,000 SHUs and is famous for its delicious flavor.


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