I made chilli oil last year from my own recipe (untried and tested!) I simply dried my chillis (in the airing cupboard) then added them to bottles of olive oil. I'm just finishing the last of the oile now - before hopefully making more from the new harvest. However, Mother in law gave us some she'd made, and her chillis were far less wrinkled - i.e. not dried. Not sure what she did to hers, but her oil was VERY potent, whereas mine was moderately so.