A special scale is used for this.
In 1912, American chemist Wilbur Scoville developed a scale to measure the spiciness of peppers based on his taste sensations. He dissolved extracts of various pepper varieties in alcohol, then mixed a drop of this solution with sweetened water and tasted it.
If the heat was felt, he continued to dilute it with water until the taste disappeared. The amount of water needed to neutralize the 'pepper solution' became the unit of measurement on the Scoville scale. Since the spiciness of peppers is caused by the alkaloid capsaicin, the scale allows for a fairly accurate determination of its relative content in a sample.
At the zero point of the scale is the bell pepper, which contains no capsaicin. The record for spiciness, recorded in the Guinness Book of World Records in 2023, belongs to the Pepper X variety and is 2.693 million Scoville heat units. The spiciness of pure capsaicin on this scale is rated at 16 million units, while cayenne pepper is rated at 50,000 units.
The Scoville method has been criticized for being based on the subjective taste sensations of the scientist and his tasters; however, improved by modern chemists, it continues to be used today. Currently, the percentage of capsaicin in a product is more accurately determined using high-performance liquid chromatography.
