Bottom Line: The Poblano chili, and its dried version the Ancho, are milder peppers, but they bring plenty of flavor.
The poblano pepper is a commonly found pod, and it is one of the larger chilis available in the market. The ancho chili is the dried version of this and is also readily available in stores (at least here in Texas). Both are milder peppers and have many uses in sauces, salsas, and other dishes that call for chilis or that could use a little kick but that you may not want to raise up to the scorching level.
The poblano is about the size of a bell pepper, but not as bulbous. Its taste is similar to the jalapeno, but I actually find it more flavorful than that more commonly used chili. It has a richness and a sweetness to it and adds more than just heat to a dish. It comes in between 1,000 and 1,500 on the Scoville scale, so it is not a particularly hot pepper and can be substituted for jalapenos if you are cooking for people who do not care much for spicy food (we pity them). I often add it to salsas along with jalapenos and/or serranos just for the additional flavor it adds. The poblano, in its roasted form, is the pepper often used when making Chile Rellenos, a particular favorite Mexican dish of mine. I also add the roasted version to my green chili sauce (and you can find the recipe for that here).
Like the New Mexico chili, the poblano has a tough skin that can be removed by roasting. It is not so tough that if you add diced fresh poblanos to a salsa or other dish people will find them hard to eat. But the roasting process adds a whole new level to the pepper’s flavor. It mellows out the chili and seems to cut the heat a bit, and makes for a very delicious addition to a recipe or something just to have on the side. (More on roasting chilis here.)
The ancho chili is the dried version of the poblano and also has many uses. The drying process does not increase the heat that much, though they tend to have a bit more kick than the fresh chilis along with a raisiny, earthy taste. Generally, you will want to rehydrate these in some water before adding them to salsa or other recipes. I will generally cut them up and remove the seeds then put them in a bowl with boiling water and let them sit at least fifteen minutes. Be sure to reserve that water as well because it has plenty of flavor from the chilis and can be added to soups, stocks, salsas, and more. You can also ground these up into a powder and add them to recipes, but it’s probably just as easy to buy pre-ground ancho powder at your local store (we have it readily available here in Texas at least). The ancho is one that I will add to my red chili sauce, and you can find the recipe for that here.
The poblano originated in Puebla, Mexico, but they are now grown widely across many regions. They are easy to find in the markets (at least here in Texas) and can be considered as a milder substitute for jalapenos or just a way to add some flavor to a dish and a little be of extra heat without adding many calories. According to TasteAtlas.com, the poblano is the fifth most popular chili in North America while the ancho is the fourth most popular.