Chilaca is a long and narrow (about 7 inches by 1 inch), dark to blackish green chile with a shiny surface formed by undulating vertical ridges. Chilacas have a slightly sweet flavor and vary from mildly hot to hot.
They are commonly used around Mexico City, particularly in the state of Michoacán, where they are also known as cuernillos (big horns), or chiles para deshebrar (chiles to shred). They are charred, peeled, seeded and shredded and used in tamales, vegetable dishes and tomato sauces. Dried chilacas are called pasillas.
Habanero is a squat chile with a slightly tapering lantern shape, about 1 3/4 inches long and 1 1/4 inches across. Its pale to medium green color ripens to yellow and then to orange (there are cultivars that ripen to a pale apricot color and others to a chocolate brown). The surface is very shiny, almost translucent, and undulating. It is often rated as the hottest chile in Mexico (although I would say one of the hottest) with a lingering flavor and aroma when charred.
In Yucatán, where it is charred and mashed with lime juice and salt, it is used as a condiment. It is also left whole, charred and added to beans or tomato sauce or can be finely sliced and added to pickled onions. It is not used dried in Mexico.
Jalapeño chile is named for its birthplace, Jalapa, the capital of the state of Veracruz, although it is now grown in many parts of Mexico. These chiles are without doubt the best known outside of Mexico because they are pickled, canned and widely distributed. There are many cultivars, but they are all unmistakable: a smooth blunt-nosed elongated triangle, about 2 1/2 inches long and 1 inch wide, whose color is a shiny medium to dark green that ripens to a bright red. Some have dark patches; others have a brown vertical striping, or corking. They are very fiery.
Jalapeños are most commonly eaten pickled as a relish; they are also eaten charred and blended into sauces. Narrow strips can be cooked with shredded meat for tamales or empanadas, and in Veracruz the whole chile is charred, peeled and stuffed with cheese, meat or fish. Ripened and smoke-dried, the jalapeño is called chipotle.
Poblano, a chile named for the valley of Puebla, where it is grown extensively, is large, fleshy and triangle- shaped with a shiny, green to blackish green color that ripens to a deep red. An average poblano is 4 1/2 inches long and 2 1/2 inches across the top; it is distinguished by a deep ridge around the base of the stalk. It has a delicious mild to hot flavor.
With rare exceptions, the poblano is charred and peeled before using. It is cut into strips and fried with potatoes or corn, stuffed for chiles rellenos or cut into strips and added to tomato sauces. It is also pureed in the blender and added to sauces and soups. Dried, it is called ancho.
This chile is erroneously referred to as pasilla in many California markets (or even fresh pasilla, a contradictory term since pasilla refers to something dried and wrinkled).
Serrano is the chile most commonly used throughout Mexico for making sauces. Generally speaking, serranos are small (2 inches long and 1/2 inch wide) and slightly pointed at the tip. They are medium to dark green with occasional dark patches; they ripen to a bright red. Their heat varies from hot to very hot.
These chiles are never skinned, nor are the seeds removed. They are chopped or crushed for fresh sauces and guacamole; simmered or charred for tomato or tomatillo sauces; cut into strips and cooked with vegetables; and very often prepared whole en escabeche, meaning lightly pickled. When left whole and slightly charred, they are known as toreados and are served with meat or soups.
Verde Del Norte is a long, skinny, bright green chile grown principally in Chihuahua, where it is called chilaca (even though it’s not a true chilaca as described above), or chile verde, and in Sonora, where it is known as chile Magdalena, named for the town that is the center of the growing area. It is similar to the Anaheim chile, which is available in California. Its smooth, slightly undulating surface ripens to bright orange and then red. Compared with other chiles, it does not have a very distinct flavor; it varies from mild to fairly hot.
The chile verde is always charred and peeled before using since it has a tough skin. It can be stuffed for chiles rellenos, cut into strips for chile con queso and chopped for sauces.