i have only done 1 chili beer ever, so take this for what it's worth, but i added (for a 20 L batch of porter) 8 chile pasilla, 4 chile mora. i deseeded them pretty well and added them dry with 5 minutes left in the boil. i also transfered them into the fermenter. the beer was not outwardly spicy, but had heat in the aftertaste. if the spritz got up your nose or in the back of your palate it stung quite a bit, and if you chugged it you felt a burn in your chest, but for sipping it was relatively mild