What Is the Scoville Scale?

Origins of the Scoville Scale

Initially known as the Scoville organoleptic test, the Scoville scale was created by Wilbur Scoville in 1912. The scale measures the spiciness of food using SHU, also known as Scoville heat units or Scoville units.

The Scoville scale is an organoleptic test because it involves testing a certain quality of food that causes responses in consumers by stimulating senses in their organs. An organoleptic test utilizes the aroma, flavor, appearance, and mouthfeel of food products to gauge certain qualities of a food, such as heat or potency.

How Does the Scoville Scale Work?

So, how does it work? At first, Wilbur Scoville developed the test by grinding up different peppers and mixing them with sugar water. Nowadays, we test peppers’ heat by extracting oil from the peppers rather than grinding them up into powder.

From that point, Scoville had people taste test the sugar water mixed solutions. As the tasters tried the mixtures and provided feedback on the heat level, he would add more sugar water for dilution in certain amounts, slowly making the mixtures less hot by decreasing their potency for the testers.

After testing various mixtures, he gave each a different rating — a number based on how many times the solution had been diluted to remove the taste of heat. Thus, the Scoville scale was born, measuring just how hot different peppers are.

An example of how it all works may be seen in how the Mexican serrano pepper is ranked at 10,000 to 20,000 Scoville heat units, meaning the solution containing the pepper’s extract has to be diluted 10,000 to 20,000 times for the heat to be essentially undetectable. Thus, the higher a pepper is ranked by its Scoville rating, the hotter it is, as it must be diluted more times to mask that heat.

What Does the Scoville Scale Tell Us?

So, the Scoville scale shows you the heat of a pepper by telling you how many times it must be diluted to remove any taste of said heat. This shows you not only the heat of certain peppers, but their heat in comparison to others. Using the Scoville scale, you can gauge how hot some of your favorite hot sauces might be and where your tolerance ranks from mild to extra hot.

The Scoville Scale in Action

The Scoville scale can be used to compare the heat of different peppers.

For instance, jalapeño peppers are mild, ranking at around 2,000 to 8,000 SHU. Other mild peppers include pepperoncini which can range anywhere from 100 to 500 SHU, or even normal bell peppers, which cap out at 0 SHU due to their sweet flavor and lack of heat.

To look at how this translates into hot sauce, our TRUFF Original Hot Sauce, which uses chili peppers as a key ingredient, ranges from around 2,500 to 3,000 SHU. On the other hand, our TRUFF Hotter Sauce ranges from 5,000 to 7,000 SHU, making it more intensely spicy as its ingredients include a jalapeño blend with red habanero powder.

But you can crank the heat up even more and look at something like Thai chili peppers, also known as bird’s eye chili peppers. This pepper can range between 50,000 to 100,000 SHU and is much hotter than most mild side dish peppers.

For another comparison, pepper spray has around 2 million to 4.5 million SHU, showing just how intense its strength is.

Examples of Hot Peppers and Their Scoville Heat Rankings

Here are even more examples of intensely hot peppers and where they rank on the Scoville scale for reference:

• Pepper X: This is currently the world’s hottest known pepper: 3.18 million SHU
• Dragon’s Breath: 2.48 million SHU
• Carolina Reaper: This pepper was previously known as the world’s hottest pepper: 2.2 million SHU
• Naga Viper: 1.3 million SHU
• Trinidad Moruga Scorpion: 1.2 million SHU
• Ghost Pepper: It is also known as Bhut Jolokia: 1 million SHU
• Mexican Red Savina Habanero: 350,000 to 577,000 SHU
• Mexican Habanero: 150,000 to 575,000 SHU
• Scotch Bonnet: 100,000 to 350,000
• Cayenne: 30,000 to 50,000 SHU
• Mexican Chile de Arbol: 15,000 to 30,000 SHU
• Mexican Chipotle: (When preserved, this pepper is better known as a jalapeño): 2,000 to 8,000 SHU
• Anaheim: 500 to 1,000 SHU

As you can see, the pepper heat levels will vary immensely on the Scoville scale depending on the type of pepper since there are so many hot peppers available at both intense and milder heat levels.

You will also notice a wide variety of peppers with intense heat levels originate from Mexico. Other examples of Mexican chili peppers that are not listed above include poblano peppers and ancho peppers (these are poblanos peppers that are smoked and made into dried peppers). Both peppers can range from 1,000 to 1,500 SHU.

How Accurate Is the Scoville Scale?

Some people may believe that the Scoville organoleptic techniques are not the most accurate tool for measuring the heat and potency of peppers, hot sauces, etc. This is because the tests are done using people as taste testers. Since different people have different taste buds, there is a lot of variation among those individuals who are testing the heat levels.

Thus, some may say the Scoville scale is not the best-chosen method for heat measurement as it can result in varying results and subtle inaccuracies. For this reason, another alternative method to the Scoville test can be used to measure heat.

Scoville Measurement Alternatives

While the Scoville test is known to be the most common method of measuring heat and potency in peppers and in hot sauces, there is another alternative method also used for measuring pungency called high-performance liquid chromatography.

High-performance liquid chromatography, also known as HPLC, uses a machine to detect and measure potency levels in peppers. Here’s how this is done:

• As chili peppers belong to the genus category of Capsicum, they contain capsaicinoids.
• Capsaicinoids are compounds that produce the pungency created when eating chilies. 
• There are two types of capsaicinoids in peppers; the main one is capsaicin, which has been found to create heat in peppers.
• High-performance liquid chromatography uses a solution and extracts pure capsaicin from different peppers.

The machine detects the amount and strength of capsaicin in the mixture. It then determines the heat level of the pepper, as measured in ASTA pungency units, which can be converted into SHU.

Why Use the Scoville Scale?

Overall, even though the Scoville methods of measurement in the original Scoville organoleptic test may be outdated and less accurate than other methods such as high-performance liquid chromatography, the Scoville scale itself still proves relevant and useful today.

The scale allows for the measurement of heat used throughout all sauces, peppers, and general foods containing some kind of spice. As mentioned previously, it serves as an indicator to display what peppers rank at what level and what heat levels are considered more intense than others.

This gives you, as the pepper and/or hot sauce consumer, a better understanding of where your preference lies for heat and what is too hot for you to eat.

How Can I Use the Scoville Scale?

When you’re searching for your next spicy dish topping, be sure to look up and consider the Scoville scale of any hot sauces or peppers you might want to add.

For instance, as we mentioned, our TRUFF Hot Sauce has a light heat at 2,500 to 3,000 SHU. If you’re interested in cooking with a light but not too mild kick, you could try using this as a sauce on our Truffalo™ Wings. 

Otherwise, if you know you typically find most jalapeños (at 2,000 to 8,000 SHU) too spicy and understand your limits on spice, you could simply try using one of our more mild spicy sauces like our Spicy TRUFF Mayo.

However you’re looking to spice up your regular dining, just be sure you’re understanding the Scoville scale. We wouldn’t want you accidentally grabbing a Carolina Reaper and overheating!

Sources:

Electroanalytical Overview: The Pungency of Chile and Chili Products Determined via the Sensing of Capsaicinoids - PubMed

Capsaicin and Dihydrocapsaicin Determination in Chili Pepper Genotypes Using Ultra-Fast Liquid Chromatography - PMC

Characterization of Different Capsicum Varieties by Evaluation of Their Capsaicinoids Content by High-Performance Liquid Chromatography, Determination of Pungency and Effect of High Temperature - PMC