I have some dried hot peppers which are over a year old. These are hybrids, part chile de arbol, but less hot so that I can use them for mixed company. A friend grew them for me specifically because of their medium hotness.
After around 16 months in doubled ziplock bags, I used some of these in a couple recipes last week, including a Mexican squash casserole. The dried peppers were partly rehydrated prior to use.
While I remember being able to use 2 or even 3 of these peppers in a recipe when I first got them, even one of them made the dish so hot I had to quickly make something else for two of our guests. This happened three times over the last couple months, so it's not just which individual pepper I pulled out. It seems like these peppers got hotter with ageing, something I'd think was impossible ... shouldn't they lose capsaicin as they age?
So, my question is:
Is it possible for a dried chili pepper to become hotter with ageing, instead of losing flavor?
If so, what causes this?
I'm guessing that it's just my faulty memory, but I'd love some verification. Thanks!