How hot is a serrano pepper?
How hot is a serrano pepper? Serrano peppers (pronounced seh-RAH-noh) are hot, literally. With a ranking of 5,000 to 15,000 Scoville units on the chili heat scale, serranos are up to five times hotter than their cousin, the jalapeño. (Jalapeños are rated at 2,000 to 5,000 units.