We get some pretty seedy questions through the contact form on seedlibrary.org so we've decided to start sharing some of our answers with everyone. Feel free to add your two cents.
Question from Cheryl:
Your seeds are what we call "after market" seeds: seeds that people saved from veggies they bought at thier farmer's market or grocery store.
It's hard to say if your seeds will breed true. Peppers, as well as many other fruiting plants like squash, eggplant, and cucumbers, need to be isolated from other varieties--otherwise they can easily cross pollinate. Most farmers who grow for markets are growing multiple varieties in close quarters. It's worth giving it a try, planting your seeds, and seeing what you get. You might get some new hybrid or you may get something close to a J-nardo Pepper. But if you want to be sure you are growing Jimmy Nardellos you need to save seed from pepper plants that have been isolated from cross-pollinating. One more tip: heat in peppers is dominant. So, if peppers do cross it's more likely they will go hot than stay sweet. So look before you leap (or nibble before you bite)!