Every cuisine contains ingredients which are in some way definitive on a cultural level, and the “intersection of food in culture, traditions and history” is really the definition of “foodways.” Given that, it would be difficult to speak about the foodways of Peru and not give a prominent place to the aji. The word "aji" simply means "chili" or "chili pepper."
There are several chilis which make the “essential” roster in Peruvian cuisine including, aji limo (often used in ceviche), aji panca (a mild, berry like chili often used to spice stews) and aji rocotto (a large spicy bulb-shaped pepper which is one of few which grow in mountain regions and is sometimes used in sauces or even stuffed like a bell pepper). Then there’s aji amarillo, the grandaddy of the ajis and, if there had to be one representative ingredient which represents the rich complexity of flavors found in Peruvian cuisine, this would be it.
If you’ve never heard of these chilis don’t feel badly. Unless you’ve been to Peru or are very familiar with Peruvian cuisine, it’s not a chili you’re going to run across by happenstance. The vast majority of aji amarillo one finds in the U.S. are dried, jarred in paste form, or fresh frozen. While one can still make respectable Peruvian food using these preserved forms, fresh aji amarillo is truly extraordinary. In spite of its name, it is bright orange. It has a meaty structure with a flavor profile is both fruity and complex, with an almost sunny medium heat that has floral notes and even a hint of raisin.
Aji amarillo comes in at 30,000 to 50,000 Scoville heat units, the standard which is used to measure a chili’s relative spiciness. This puts it in the same general level of cayenne and tabasco peppers. It sits right in the middle of the medium heat section of the Scoville scale.
Aji amarillo is part of a species of chili peppers called capsicum baccatum, which has its origins in ancient Peru and across the Andean region of South America. Baccatum are some of Earth’s oldest chilis, as evidenced by early cultivars having been found in caves in Southern Peru dating back to 8500 b.c.. Other members of capsicum baccatum include peppadew, lemon drop and bishop’s crown, though aji amarillo is its star.
There are several other notably historic peppers that deserve our admiration and attention, on the plate, in a cultural context and in the lab. But in our examination of the foodways of the chili pepper, it seems fitting to begin at the beginning, with some of the first, and most extraordinary wild and cultivated varieties in the world, many of which are found in Peru.