Common Chile Peppers and their SHUs

Chile pepper heat has been an object of tremendous interest for a long time.  Way back in 1912 Wilbur Scoville developed the Scoville Organoleptic Test.  It is a subjective test - but a well designed succesive dilution test.  He used a panel of testers to taste pulverised peppers diluted in sugar water.  The titer was to the point of not being able to tell the difference of the diluted hot pepper with an undiluted ripe bell pepper (therefore the sugar since ripe bell peppers are sweet and hot peppers usually are not).  The amout of dilution needed gives the Scoville Heat Unit (SHU). 

Wilbur Scoville assigned an arbitrary heat of 100 to sweet bell peppers so that an Anaheim with an SHU of 1,000 is ten times hotter than an average sweet bell pepper.  Other sources seem to indicate that a sweet bell pepper has a heat of zero but that would make everything else infinitely more hot - which is not the case.

The current, somewhat more objective method, is to measure capsaicinoids concentrations with HPLC.  This method yeilds results in parts per million (PPM).  Divide the HPLC PPMs by 15 to get the SHUs.

A list of the most common chile peppers with their SHUs:

For more information on the SHU values for chile peppers refer to the New Mexico State University publication NMSU Guide H-237 Measuring Chile Pungency.