We had a good harvest of chillies this year from our greenhouse and polytunnel. Too many to use fresh, despite my husband becoming addicted to slicing them raw on almost every meal put in front of him. What is he saying about my cooking? So we decided to dry them and crush them. We are very lucky to have an Aga, which has a warming oven that allows us to pop these in and leave them until they are ready. They take a good twelve hours at least so this will be harder to achieve with a standard oven that you need for cooking other meals.
All we did was to place them whole onto a grill rack on a baking tray and with the oven at its lowest temperature we left them in the oven until completely dry. We then allowed them to cool completely before grinding them in the pestle and mortar. We put them into a sterilised jar and they should keep for ages to add a spicy kick to our dishes throughout the winter.
Drying them makes them hotter than they were fresh so less dried chilli is needed when using in recipes.