THE SCOVILLE SCALETHE SCOVILLE SCALE
In 1912, a man named Wilbur Scoville felt the need to develop a system where he could rank the hotness of peppers. He is now known as the famous (in chile pepper circles that is) inventor of the Scoville Organoleptic Test - also known as the Scoville Scale (Bosland, 2002).
Scoville conducted a series of tests with whole ground chile peppers mixed in a solution of water and sugar (Avakian, 2002). He then had a panel of five taste testers sip the solution in increased dilutions until it reached the point that it no longer burned the mouth (Avakian, 2002). A number was then assigned to each pepper based on the amount of dilution required before the effects of the capsaicin could not be felt. One part of pepper-heat per one million drops of water was then rated at 1.5 Scoville Heat Units (SHU) (Avakian, 2002). The measure is still used to this day by spice companies and sauce manufacturers around the world (Saaristo, 2002). If all known peppers were measured using this technique, their scale of pungency would range from 0 Scoville units, for the bell pepper, to 350,000 units, for the Mexican habanero (Saaristo, 2002). 100% pure capsaicin is 16 000 000 Scoville Heat Units! (Saaristo, 2002).
Interestingly, Scoville ran into problems with his method due to the fact that no one's perception of hot ever agreed. Therefore his panelist's estimates had to be averaged (Saaristo, 2002). Naysayers argued that the tongue is too subjective to base an entire scale on, but Scoville replied that the tongue is senstive to less than a millionth of a grain, which certainly has its advantages (Saaristo, 2002). Scoville also ran into trouble with the number of tests his panelists could perform per day because human tongues temporairly get used to certain levels of pungency and have to be given a rest (Saaristo, 2002). In an eight hour period, no more than six samples could ever been run through the panel (Saaristo, 2002).
| Type of Peppers | Scoville Heat Units (SHU) |
| Most Bell and Sweet Peppers | 0-100 |
| Anaheim & New Mexico peppers | 500-1000 |
| Jalapeno & Mirasol Peppers | 2500-5000 |
| Yellow Wax & Serrano Peppers | 5000-15 000 |
| de Arbol Peppers | 15 000-30 000 |
| Chiletepin Peppers | 50 000-100 000 |
| Habanero Peppers | 200 000-300 000 |
Nowadays scientists use High Performance Liquid Chromatography (HPLC) to measure the heat (or capsaicinoids) in chile peppers. Thirty samples can now be tested within 8 hours, and accuracy is not a concern (Saaristo, 2002). A sample is refluxed with ethanol for five hours and the resultant mixture is filtered. The HPLC machine is standardized with oleoresins and a 20mL sample is injected into the machine (Bellringer, n.d.).The results are chromatograms that look similar to those found below, depending on the type of pepper analyzed.
HPLC allows the amount of individual capsaicinoids to be determined. There is still however, a reliance on the Scoville scale which is then used to classify the pepper. The relative retention times of some capsaicinoids are: capsaicin, 1.00; nordihydrocapsaicin, 0.90; and dihydrocapsaicin, 1.58 (Bellringer, n.d.). HPLC measures the amount of capsaicinoids in ppm. An easy way to convert ppm to SHU is to simply multiply by 15 (Bosland, 2002).
