Hi! I don't know what datil peppers are.... have you googled them? I know that I just pick my other kind of peppers when they are big enough for the recipe I am using. Are they hot peppers? If so, I guess you know you have to be very careful in cutting them open - you don't want the juice on your skin -- or worse, in your eyes!
Hey - I don't know how to do the link thing, but I just googled them. There is a lot of info! Try there and see if anything is helpful!
Good luck!

@tansu...I can't believe that no one has commented back to you. I just thought I would answer your questions. As far as "which kind"...I don't know what you mean..but there are only one kind to my knowledge. I have been growing them for years (my Grandfather and my Father started me on growing them). A little about the pepper...Green is premature, Greenish Yellow with a purple vein is when they are at their hottest, and Yellow to Orange is when they are ripe and ready to pick. In order to store them, you can store them at room temp. for a few days to a week but if you aren't going to use them right away, then simply put them in a plastic bag and throw them in the freezer. They will keep. To save the seeds, I usually use a yellowish orange pepper, slice it sideways and pull the seeds out (I ALWAYS WEAR GLOVES). Simply pull the seeds apart gently and then place them on a paper towel for a week to 10 days. I then store them in coin envelopes and store them for up a to a year. I have sent seed packets of 25 count to friends all over the country and have never had a complaint of seeds that didn't sprout and produce. I don't know if you still read this blog, but if you do and want some recipes or even some more seeds, just send me a message back. Thanks and happy growing!