Chipotle chilies are dried and smoked jalapeño peppers. They have a wrinkled, dark brown skin and a smoky, sweet, medium-to-hot flavor. Select dried chilies that are slightly pliable; store them in an airtight container in a cool, dark place for up to 6 months. Before using, rinse under cool running water to remove any dust; then cover with very hot (not boiling) water and soak for 15 to 20 minutes, or until softened. (Do not add the soaking water to recipes because it can be bitter.) Like fresh chilies, the seeds and the membranes contain most of the capsaicin - the compound that makes chilies fiery; removing the seeds and veins is the only way to reduce the heat. To avoid burns, use disposable plastic gloves when handling hydrated (or fresh) chilies. The easiest way to chop them is to use kitchen scissors; cut the seeded halves into strips, then snip across the strips into small squares.