Chilcosle (chilcostle) chiles are a bright red-orange color and grow to be about 3 to 5 inches long. The chile is native to Cuicatlan, Oaxaca, Mexico and is a relative of the chilhuacle rojo. The heat produced by the chile is moderate, about 5 on a relative heat scale of 1-10 with 10 being the hottest. Chilcostle chiles have a slightly sweet flavor and it typically used in cooked sauces, tamales, and mole amarillo.
Note: Diana Kennedy spells this chile "chilcosle". Diana Kennedy is one of most well-known experts on Mexican cuisine. Mark Miller, author of The Great Chile book spells it "chilcostle".
Production of the chilcosle chile is small. Local growers can make more money per pound for the prized chilhuacle negro so less effort is put into growing the lower-demand chilcosle chile. Because of this the price of these chiles is very high if you can find them at all. A few online websites sell them, SpiceTrekkers, Kalustyan's and Oaxacanspice.com. If you're interested in growing chilcosles, you can purchase seeds at Amazon.com: Chilcostle Rojo Seeds.
If you don't have chilcosle chiles then you can substitute: