This is a bit of a detour, but I would like some clarification about the term "pepperoncini." Sometimes it refers to crushed red peppers, regardless of whether it is a single origin pepper or a mix of cayenne and other peppers sold often as simply "crushed red peppers." And other times it refers to the green pickled relatively mild peppers. Is there a single type of pepper used both in its green phase and then dried when it turns red and crushed up to be served as dried red flakes.
Most mixed crushed red pepper flakes are hotter than the green pickled peppers that are called pepperoncini. If indeed the crushed red pepper sold in spice jars (or if you are making it yourself from a variety of peppers) is often heavy on cayenne, then what is the specific pepper that is ubiquitous as an Italian pickled fresh pepper? In my experience with various types of fresh peppers and dried, I have no proof that a fresh mild green chile will become hotter as it ripens and turns red, but is that a factor?
According to Lidia B it is a pepper specific to Calabria and is used in all forms. What do you think?