Ancho chiles are a type of dried chile pepper commonly used in Mexican and Southwestern U.S. cuisine. The pepper is the dried version of is the poblano pepper—to be specific, it's the dried version of the ripe version of the poblano pepper.
In other words, the chiles we know as poblano peppers are fresh chiles that are harvested before ripening, which is why they're green. It's what your basic chile relleno is made with. But when allowed to ripen, poblanos turn red and develop additional sweetness, which in turn balances out their already mild heat. Thus anchos are red while poblanos are green.
Incidentally, the word ancho translates to "wide" in English, while poblano refers to the state of Puebla in central Mexico where the peppers are supposed to originate.
Working With Ancho Chiles
Ancho chiles can be reconstituted by soaking them in warm water, or they can be ground up or crushed and added to a recipe in that fashion.
Drying the chiles don't affect their heat, although the way the heat is transmitted will depend on how finely crumbled/ground they are, and whether they're reconstituted first or not. In other words, crumbled up chiles will give you a more localized spiciness whenever you happen to get a piece (or several) in a particular bite. On the other hand, ones that are reconstituted first and then puréed will disperse their heat more evenly throughout.
Ancho chiles have a deep red color and a wrinkled skin. Sweet and smoky with a flavor slightly reminiscent of raisins, their heat is mild to medium-hot.
You could also use a spice grinder to grind dried ancho chiles into a powder to use in spice rubs or for making mole, enchilada sauce, and chili.
Tasty Ways to Use Ancho Peppers
Ancho sour cream will change your life, but only if you use full-fat sour cream. (If you use reduced-fat sour cream, it will still taste great, but won't rock your taste buds the same way!) Soak the dried pods in hot water for 30 minutes, then remove the seeds and stems. Combine the reconstituted peppers with some sour cream and purée until smooth.
Serve with baked potatoes, stir into mashed potatoes or simply enjoy with any food you already eat with sour cream.
You could also use a similar approach to make a spicy ancho cream sauce to serve with enchiladas—but instead of sour cream, use Mexican crema.
Fast Facts About Anchos
Ancho chiles register between 1,000 and 2,000 Scoville heat units, which means they're quite mild. They're sometimes incorrectly referred to as pasilla pepper (as are poblanos, for that matter) but they're not the same thing.
Is it chile or chili? When you're talking about the peppers—anchos, jalapeños and so forth, it's chile. When you're talking about the delicious one-pot recipe you make with stewed meat, beans, and spices, that's chili. (And if you're talking about the nation that happens to be the longest in the world when measured north to south, and also happens to be one of the world's top wine producers, then you mean Chile.)