Chipotle chillies are smoked, dried jalapenos. Jalapenos are green for most of the growing season, but turn red in the fall. For Chipotle the peppers are allowed to stay on the plant until they turn deep red and begin to dry out. Theses deep red jalapenos are smoked for days until completely dry. It takes about 5 kg of jalapenos to make a 500 grams of chipotle.
The Aztecs knew that some sorts of fleshy chillies, nowadays known as Jalapenos, cannot be preserved through drying through air. Because of that they tried the same method which was successfully used on meat and fish: they dried the chillies with the help of smoke. Even today with this reliable method of the ancestors we handle the smoking in origin: Pits are dug out, which are connected through an under earth tunnel. In one of these pits a fire is kindled, in the other one are the chillies lying on a metal stand. The draft lets smoke go over the chillies, so they are dried and smoked at the same time. The result is a typical and unique Mexican product: Chipotle.