Scoville Unit 101
What is a Scoville unit?
A Scoville unit is a measure of heat, less frequently referred to as the "pungency" (or spiciness) of chili peppers. The name comes from Wilbur Scoville, who came up with the heat rating method in 1912.
How are Scoville Units measured?
Scoville Units are measured by what's known as a Scoville organoleptic test. (Say it with us now, "or-gan-ol-ep-tic.") The test is a method for estimating Scoville Heat Units (SHU) and is actually a relatively subjective measurement. (Weird, we know.) It's derived from the capsaicinoid sensitivity people experience when eating chili peppers.
How does that work exactly?
Great question! In the Scoville organoleptic test, dried pepper is measured in an exact weight and dissolved in alcohol to extract capsaicinoids (heat components). That mixture is then diluted in a sugar water solution.
From there, a panel of five trained taste testers are given decreasing concentrations of the solution until a majority can no longer detect heat. Heat level is then rated in multiples of 100 SHUs, based on the dilution.
Is that really how they get Scoville Unit ratings today?
Yes and no. It's kind of confusing. Today, spice heat is assessed quantitatively by high-performance liquid chromatography (HPLC), which measures capsaicin content or concentration of heat-producing capsaicinoids.
From that measure, the HPLC results are then typically converted back to Scoville Units by multiplying parts-per-million of capsaicinoids by 16.
So what does that mean? In summary, the way SHUs were originally measured is no longer in practice, but the current method reverts their results to SHUs since they're commonly known and used.
Why do I need to know what Scoville Units are?
There is a vastly wide range of spiciness out there, friends. If you don't care if you burn your mouth with every dip, lick or bite, you can read right past this! For those of you who are a little more cautious, Scoville Units can save you!
Scoville Units start at 0 and reach up to 15-16 MILLION on a scale. That's some variance! Our chart below breaks it down so you can see where your favorite sauces (and/or your tolerance) lies.
How do Scoville Units of sauces compare to those of peppers?
You ask all the right questions! Scoville Units measured directly from peppers give concentrations that are drastically more potent that hot sauces themselves. For example, a Carolina Reaper can measure in at 2,200,000 SHUs, but you won't find a sauce with Carolina Reapers at a similar heat rating.