The ubiquitous chile jalapeño is popular all over Mexico and the world, at points north, south, east, and west. The jalapeño measures anywhere from 2" to 3" long and rates between 10,000 and 20,000 units on the Scoville scale. It's the chile most people outside Mexico think of when they think Mexican food.
Chile--hot, savory, wonderful chile--has been part of Mexico's culture for thousands of years. The Nahuatl name is chilli. Chile, corn and beans formed the indigenous dietary base for thousands of years before the Spanish first sailed into the bays of what they called the New World.
Here in Mexico, we've learned to distinguish the qualities of different types of chile not only by their colors and forms but also by the degree of heat they impart to our foods and palates. Picor (heat), as subjective an experience in the mouth as one's experience of sweetness or sourness, ranges from a disappointed shrug to holy Moses, bring the fire hose!
Chile poblano, usually mildly picante (heat-producing), has a distinctive, rich flavor to match its deep inky-green color. The poblano usually measures about 6" to 7" long, 1,000 to 2,000 Scoville units, and is most commonly used to prepare chiles rellenos. Once in a while a poblano will surprise with more heat than you expect! One of the most delicious preparations using chiles poblanos is the seasonal Chile En Nogada--stuffed chiles poblanos in walnut sauce.
Wilbur Scoville, an early 20th Century American chemist, quantified the heat factor of various chiles and left us all with an approach to picor more scientific than simple subjectivity. His objective scale of heat ranges from 1 (the sweet red bell pepper) to a possible 325,000 (the chile habanero). What Scoville didn't quantify was flavor; chile is more than mere fire.
Chile güero (blond chile, about the size of a jalapeño) is only slightly higher on the Scoville scale than chile poblano. These chiles, like jalapeños or serranos, are often hand-rubbed to loosen the seeds, oiled, grilled, and served as chiles toreados, alongside an order of tacos.
Chile chilaca, grown extensively in Queréndaro, Michoacán, is widely used in Michoacán but is not as well-known outside this region. It measures between 8 and 10 inches long and is 2,500-5,000 Scoville units.
Chile de árbol (tree chile) is picked green to use as a fresh chile and allowed to mature to bright red for different uses as a dried chile. It's usually 3" to 4" long. It's a good bit hotter on the Scoville scale than previous chiles: 15,000-30,000 units.
Chile manzano (aka chile perón), about as big as a golf ball, packs a punch: 30,000-60,000 on the Scoville scale. The manzano is hot, but also very floral in flavor. It's usually used in encurtidos (pickled vegetables with chiles).
The small but infamous chile habanero (Havana chile) is arguably the hottest fresh chile grown in Mexico, ranking as high as 350,000 Scoville units. Merely slit open and passed through some salsas, the habanero leaves just a hint of its tremendous heat after it's removed from the salsa. In spite of its name, this chile originated in southeastern Mexico, not in Cuba.
Chile serrano, about 3" long, is not the hottest chile in Mexico (Scoville ranks it just a tiny bit hotter than the jalapeño), but it may well be the most-used. The serrano is known by other names: chile verde is the most common of these. Generally it's eaten green; the red ones have been left to mature on the bush.
Next week in Mexico Cooks!: a collection of dried chiles.
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