What Are Serrano Peppers And How Spicy Are They?

A variety of hot peppers named after the mountain region in Mexico they hail from, Serrano peppers are a spice-packed chili used in Mexican cuisine almost as much as jalapeños; they can also be found in Southeast Asian cooking (via The Spruce Eats). Known scientifically as Capsicum annuum (via Organic Facts), Serrano peppers are narrower, shorter, and significantly hotter than a jalapeño (via Pepper Scale). Additionally, aside from the seriously spicy punch they pack, Serrano peppers are jam-packed with nutrients; one cup of chopped peppers delivers 3.9 grams of fiber, 1.8 grams of proteins, 7 grams of polyunsaturated fat, and a variety of vitamins and minerals (via Verywell Fit). 

Not only is the impact of the heat delivered by a Serrano pepper delayed (meaning that its spiciness isn't usually felt until a moment after coming in contact with the palate), a standard Serrano pepper measures between 10,000 to 25,000 units on the Scoville scale, compared to a jalapeño's 2,500 to 10,000 Scoville units. When comparing the weakest jalapeño to the strongest Serrano, the latter can measure up to 10 times hotter than the former.

What makes Serrano peppers spicier than jalapeños?

According to Verywell Fit, the Scoville scale rates a pepper's spiciness based on the amount of capsaicin found within the fruit, which is the compound responsible for giving hot chili peppers their heat. The Spruce Eats explains that the highest concentration of capsaicin within a chili can be found in the pepper's seeds, veins, white pith, and the innermost layer of flesh — and Serrano peppers carry a lot of it. Capsaicin triggers the tongue's pain receptors (the same receptors that feel heat), which is why the spicy effects of a Serrano chili have been described by some as "fiery" and "sharp." According to MasterClass, the smaller the chili, the more heat it packs.

As consequential it can be to a chili's heat rating, capsaicin might cause redness and inflammation, but it won't cause any permanent physical damage to the body. According to Organic Facts, while some may think that the hotter a chili is the more inflammation it will cause, the spice-delivering components of chili peppers can actually help reduce inflammation throughout the body. Spicy chili peppers can cause immense discomfort externally, however, so it's incredibly important when handling Serrano peppers to avoid getting the chili's oils on your hands or near your face (via The Spruce Eats).