If you've ever made fried chicken, you know how hard it can be to replicate the satisfying, crunchy crust perfected by KFC or Popeyes.

But, according to a food scientist, one surprising ingredient could do the trick: vodka.

That's what J. Kenji Lopez-Alt, managing culinary director of food-enthusiast site SeriousEats.com, found after hundreds of experiments in the kitchen.

The reason vodka is the ideal ingredient for a fried-chicken marinade mixture is rooted in science, Lopez-Alt said.

In order to maximize the crispiness of the chicken, it makes sense to maximize its surface area.

"With a food like fried chicken, you want it to be really, really crisp," Lopez-Alt said on Stephen Dubner's "Freakonomics" podcast in November. "And the more surface area you have, the more sort of little nooks and crannies you have, the crisper it's going to feel in your mouth, the better sauce is going to cling to it."

Using vodka will increase that ratio of surface area to volume. Alcohol is more volatile than water, so it evaporates more rapidly and violently than the water in a typical marinade ingredient, like buttermilk.

This results in bigger vapor bubbles that turn into those extra nooks and crannies of fried goodness.

Vodka's lower boiling point also drives moisture off the crust faster, ensuring that your chicken will come out light and crispy.

You can apply the same theory to other fried foods, including fish, corn dogs, and onion rings, Lopez-Alt said. And you're not just limited to vodka.

"I use vodka because it doesn't have a taste, but any hard alcohol will do the job," Lopez-Alt told Business Insider. "Bourbon, gin, scotch, I've done it all. You'll be fine, as long as you're OK with your fried food tasting like bourbon."