Actually, you can pick japs anytime you like. Once they start turning red, the flesh will take on a sweet taste, but still have some heat. Picking size will vary on the particular strain you're growing. I would suggest you let some stay on the vine until they are bright red, any longer and they will start to go quickly. If you freeze fresh japs, they'll lose texture upon thawing. Reds are great for smoking, dehydrating, and grinding into chile powder. You can also do the same with the green ones. Was I through?