If you leave them on the plant, they will start to wrinkle. Still usable but I tend to use the wrinkly ones for next years seeds.
Taste them, if they are the right heat for you at green, pick them green, or if you want them hotter, wait until red.
I picked some green Pequins just to put into a chutney, was going to use 2 or 3, but after slicing one, I tested the heat by putting the cut off stalk end on my tongue, :o just one went into the recipe.
Chillies freeze whole extremely well, no prepping needed, just bung them in a small tub (500g margarine tubs are ideal), and take out as needed.
Don't try to chop when frozen rock hard as you will probably take your finger off, a quick roll between the palms soon softens them up enough to slice safely.
