The Scoville Scale has been instrumental in providing chilli pepper enthusiasts and culinary professionals with a standardised and relative measure of heat intensity. Whether you're a spice aficionado or simply a curious eater, the Scoville Scale continues to serve as a valuable tool in navigating the realm of chilli pepper heat.
After a decade of holding the title of the World's Hottest Chilli, the Carolina Reaper has been dethroned by Pepper X. Grown by Ed Currie of the Puckerbutt Pepper Company in South Carolina, USA - who also created the Carolina Reaper - this searingly hot chilli ranks at a whopping 2,693,000 Scoville Heat Units (SHU).
But how do we measure which chillies make the cut? Few culinary ingredients have captivated the taste buds and ignited passion like chillies. These fiery berry fruits (no, they're not technically vegetables) have been integral to cuisines around the world. Known best for infusing dishes with a spectrum of flavours and a scorching heat that leaves an indelible impression. Chillies have a rich history that spans centuries and continents. Originating in the Americas, they were introduced to Europe and Asia through the Columbian Exchange during the 15th and 16th centuries. These vibrant species, which come in an array of shapes, sizes, colours, and levels of heat, quickly found their way into diverse culinary traditions, transforming countless recipes along the way.
Why Was The Scoville Scale Needed?
For a long time, gauging the intensity of chilli peppers was subjective and imprecise. Terms like "mild," "hot," or "very hot" were used, but they lacked the precision necessary to communicate the true heat potential of these fruits. This led to the development of the Scoville Scale, a standardised method to quantify and compare the spiciness of different chilli peppers.
The Invention of the Scoville Scale
In 1912, an American pharmacist named Wilbur Scoville quite by accident stumbled on a test to measure the heat of chilli peppers accurately. At the time Scoville was working for a pharmaceutical company called Parke-Davis and was trying to devise a way to improve the efficacy of their muscle relaxant and pain killing cream called Heet liniment, which used capsaicin as its main active ingredient. His approach involved creating a dilution series using a sugar-water solution, in which an exact weight of chilli pepper extract was added. A panel of tasters would then sample the solution and rate its dilution level until the heat was no longer detectable. This process allowed Scoville to assign a numerical value to each pepper based on its dilution level, known as Scoville Heat Units (SHUs).
How Does The Scoville Scale Work?
The Scoville Scale measures the concentration of capsaicinoids, the chemical compounds responsible for the heat in chilli peppers. Capsaicin, the most prevalent capsaicinoid, binds to pain receptors in the mouth, creating a sensation of heat. The higher the concentration of capsaicinoids, the hotter the chilli pepper.
The Scoville Heat Units (SHUs) provide a relative measurement of the heat level. For instance, a sweet bell pepper would have a SHU value of 0, while the Carolina Reaper, one of the world's hottest peppers, can reach a scorching 2.2 million SHUs. This means that the extract from the Carolina Reaper must be diluted 2.2 million times with sugar water before the heat is no longer perceptible.
How Effective Is The Scoville Scale?
There was one slight problem with the Scoville method, it was always dependent on the tastes and tolerance of the taster. Each person has a different number of heat receptors and a different palate which could be further affected by taste fatigue over the years. As such, it was reasoned that the Scoville Scale was ultimately too subjected. The Scoville Scale has since evolved to incorporate more precise and objective methods. High-performance liquid chromatography (HPLC) and gas chromatography (GC) are now used to directly measure the capsaicinoid content, providing more accurate and reliable results. This has led to the development of the modern Scoville Heat Unit (SHU) based on capsaicinoid concentration.
While the Scoville Scale remains popular, it is important to note that it is no longer the sole reference for chilli pepper heat. The industry standard is now the HPLC-based measurement, which directly determines the capsaicinoid concentration in parts per million (ppm). Wilbur Scoville's groundbreaking test laid the foundation for understanding and appreciating the diversity of chilli peppers, enabling us to explore the world of fiery flavours with greater confidence and precision. And while it may not be considered the most scientifically accurate method to determine heat anymore, for historical and nostalgic reasons, the Scoville Scale is still widely recognised and used in the culinary world as the indicator for heat.