Peppers self-pollinate rather easily. If you want to make sure you get a pure seed stock you can find a flower bud that's plump and very close to opening and "bag" it by covering/tieing up a piece of cheesecloth (or similar) loosely over the bud. Later in the day and/or the next day or two give the stem the bud is on a little shake to help it pollinate itself (not necessary, but helps). A day or two later you can remove the bag and let the pepper grow itself out. Collecting seed from these peppers give you an unmixed/unhybridized seed source direct from the parent. It's usually a good idea to bag multiple peppers, and to do it on multiple plants if possible.

Isolation (planting peppers far apart from each other) is a less labor intensive method. You can plant a "seed collecting plant" far away from your other peppers and severely lessen the chance of pollination from another plant.

About hot/sweet peppers mixing. Though some sweetness has shown up on some hybrid hot/sweets, the genes for heat are extremely dominate and rarely will a "tameness" occur when bred together.

This post was edited by nc-crn on Mon, Dec 31, 12 at 19:01