Spicy food has always been an interesting topic to me. You willingly (for the most part) eat something that will cause you a certain amount of pain, and you enjoy it enough to take another bite. I don’t quite understand it (I’m a chemist, not a neurologist), but there is one thing I know for sure: despite the pain, I love spicy food.
You may have heard of some info on how to know the spiciness a pepper is, like Scoville units and the like, but how exactly are peppers ranked by their spiciness? Before we get into that explanation, let’s begin with the basics: the compound in a pepper that we interpret as “spiciness” or “heat” is called capsaicin. Capsaicin is classified as an irritant, which is why we feel that tingling sensation after biting into a jalapeno: that’s the capsaicin molecules interacting with the mucous membranes in your mouth. Aside from us enjoying the tingling sensations that it provides, capsaicin’s main purpose is to act as a deterrent to keep away animals that may want to eat the pepper plant; this is known as a plant defense against herbivory (sometimes also referred to as host-plant resistance or HPR), a mechanism that a plant uses to increases its likelihood of survival by deterring herbivores from eating it. Too bad us humans enjoy the heat.
Over the years, a rating system known as the Scoville scale has been developed as a method to rank peppers by how spicy or “hot” they are. The Scoville scale is based on the Scoville organoleptic test, a highly subjective method of determining the amount of capsaicin in a pepper. Here’s a basic breakdown of how the Scoville organoleptic test works: an exact amount, measured in grams, of a specific dried pepper is dissolved into alcohol to extract the capsaicin from the pepper. After allowing the capsaicin molecules to dissolve, a series of different dilutions are made using sugar water. A panel of five professional tasters then taste these different dilutions, each of which have different concentrations of the capsaicin from the dried pepper, until at least three out of the five taste testers agree that they can no longer detect the capsaicin in a specific dilution. Based on which dilution that is, the spiciness of that pepper is then translated into Scoville units by units of 100 (e.g. there is no such thing as a unit of 250 Scoville units, only multiples of 100).
Now, it’s quite easy to see the potential issues with such a test. It is quite unlikely that these five professional tasters, no matter how truly talented their palates are, that they represent everyone’s tasting abilities equally. A rating of 5000 Scoville units feels differently to me than it does to my older brother, who would eat whole habaneros for fun; on the other side of the spectrum, my mother is highly sensitive to capsaicin and even asphyxiates at the smell of spicy food (let’s just say that family dinners were very… interesting). Additionally, professional tasters can experience sensory fatigue after tasting so many spicy samples, which may affect their tasting judgment. Bottom line, assigned Scoville unit ratings are only moderately helpful, highly subjective, and have different meanings to different people.
I like to add another level of spice to my tacos by making cayenne pepper tortillas. They turn out beautifully orange and provide a little kick to every bite. Nate loves to eat them with hummus, so to each their own.