(FORTUNE Magazine) – A bright idea is one thing, but stick-toitiveness can be far more important when developing a new product. It took 432 tries and nearly three years, but Oklahoma entrepreneur Stewart Kennedy, 29, says he and a team of food researchers at Oklahoma State University have finally perfected their formula for individually wrapped peanut butter slices. (Think Kraft Singles.) Now in test markets with Wal-Mart, Albertson's, and other retailers, PB Slices could be coming to a store near you very soon. FORTUNE caught up with Kennedy to talk about how he developed the idea, how he's protecting it, and what makes a good PB&J sandwich.

Q: Why does the world need sliced peanut butter?

A: Well, people are too lazy to take out a knife and cut off a piece of cheese, aren't they?

Q: Guess so. Any other reasons?

A: It's just more convenient. No knives. No spoons. Makes our lives less stressful. And it's easy for little kids to take it with them or to roll around a piece of fruit.

Q: How'd you come up with it?

A: I was playing cards at a friend's house, and we were talking about crazy food ideas. One person said her mother wanted sliced peanut butter because regular peanut butter tears the bread when making a sandwich.

Q: Why was it so hard to develop?

A: It was sticking to the plastic. Or if it didn't stick to the plastic, it tasted like crap. It's easy to make a rubbery slab of peanut butter stuff. But to make a true peanut butter slice--that's hard.

Q: Sounds frustrating.

A: We got so tired of eating peanut butter, it drove us crazy. We'd have 40 different prototypes, and none of them was right.

Q: Did you ever feel like giving up?

A: A few times. We thought we had the perfect product. Then we found out that the ingredient we used to release it from the plastic wasn't approved to be in the food chain.

Q: What was it?

A: A food-grade wax. At home, you can use as much of it as you want. But commercially you can only use like 0.01% or 0.001%. We had an ungodly amount. We'd spent three months thinking this was the one. I just wanted to puke.

Q: I hear you've rigged it so none of your producers can steal your formula.

A: We have three different stages in the production process, and at each stage there are different ingredients added, so no one company knows the full ingredients. That's just safety. Plus we have patents pending. And if you steal the idea, the university is going to call you a bad person because you'd be taking money away from their children.

Q: Have you always been a peanut butter nut?

A: Not really. My biggest thing was peanut butter mixed up with waffle syrup. I'd put it on biscuits, pancakes, and waffles. I grew up on that.

Q: Oh.

A: They don't have that in New York? Must be an Oklahoma specialty-food item.

Q: What's next for you?

A: We're coming out with a crunchy and a thick. Crunchy is harder to make because the peanut pieces poke through the plastic.

Q: What about sliced jelly?

A: It's already out there. It's called a Fruit Roll-Up. But the problem is that it doesn't have any moisture, so it doesn't work in a peanut butter and jelly sandwich.

Q: Why not?

A: A PB&J has to have "squoosh." The squoosh factor is very important. If you have sliced jelly you don't have the squoosh.