The Scoville Scale

In 1912 American chemist Wilbur Scoville created a method of measuring the "hotness" of chili peppers. The resultant Scoville Scale is a measure of the piquancy of a chili pepper. The number of Scoville heat units (SHUs) indicates the amount of capsaicin present.

Basically the pungency of the chilli depends on the location in which chilli is grown and the genetic structure of the chilli. The pungency of the chilli is due to the capsaicin, a chemical compound found in placenta of the chilli. Capsaicin stimulates the nerve endings in the tongue which transmits to brain making the body release endorphin.

Wilbur Scoville tried many different methods to measure the pungency of the chilli, but he found that the readings were not precise and consistent. He tried to mix the chilli extract with different chemical but was not successful. He found that subjective test were more successful. The tongue being sensitive reacted to the pungency of the chilli. He soaked the chilli in alcohol. The capsaicin is soluble in alcohol.

The quantity of the soaked extract is noted. Water mixed with sugar is added to the extract and given to the human subjects to taste the sample for pungency. Usually, there are five people who taste the sample. To achieve the rating, three people out of five must agree on the taste. If there is still pungency found, then the samples are further diluted with solution of alcohol and sweetened water until there is no heat felt by the tasters.

The following table shows the approximate SHUs of various types of popular chili peppers

		Of the known chili varieties, the hottest chilies currently on record (2008) are the Naga Jolokia (India) and the Dorset Naga (UK) measuring a maximum of 1,001,300 and 970,000 respectively. As these varieties are uncommon, they have been excluded from the above chart. The Dorset Naga is sold with the following warning: [Warning: this chili is extremely hot; please use with the greatest caution. *Under no circumstances should one of these chilies be left where an unwitting person, especially a child, might handle them*.]	Click Here
		Red or Green - Is there a definitive answer? Not really. Green chilies are the unripe fruit whilst red chilies are ripe. "So which is hotter, the red or the green?" The answer is: it varies. Experts tend to agree that the green is usually a little hotter, while the red is considered to be somewhat milder but more pungent. Some consider the red to be more consistent in it's heat level, whereas the green is more likely to vary between extremely spicy and not so spicy.