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It's a rare occurrence 'round these parts that a pile of french fries will go unfinished, but what happens when they do? There's nothing much more depressing than discovering that what once was a heap of crisp-on-the-outside-fluffy-in-the-middle, potatoey treats has become a uniformly mushy, grease-laden mound of sadness. And that's really what old, soggy fries are.
What's a crispy potato lover to do? You could try reheating them in a hot oven. It works, but your fries come out a dry shadow of their former selves. You can refry them, which actually works spectacularly, but also requires that you heat up your fryer. You can do what I used to do: feed them to the pups as a treat.
But no more. For I have discovered what might be the absolute best way to reheat fries: in the waffle iron. It's certainly the best use for the waffle iron we've discovered since waffle pizza.
Conceptually, it's pretty similar to The Waffleizer's Hash Brown Waffles: both are made with thin-cut potatoes pressed into a waffle iron. The end results, however, are vastly different.
The fries go in cold and get compressed into the waffle compartments where they begin by shedding some of their fat, then continue by frying in that fat.
They take a little longer than you'd expect—10 to 15 minutes or so—but you'll know they're ready when every nook and cranny is fully crisped.
We served ours with a bit of the awesome chipotle mayonnaise from Just Mayo.
So what makes them so good you ask? What makes them so different from waffle hash browns?
Well, waffle hash browns are made from raw shredded potato, which means that there's still quite a bit of sticky starch on the surfaces of the shreds. When you waffle them, they form a cohesive solid; They need to be cut with a fork and knife, and they behave very much like regular hash browns, albeit with more crispy surface area.
French fries, on the other hand, are pre-cooked and have no such sticky starches on their surface. Quite the opposite in fact: they have greasy surfaces that don't want to stick together.
The waffle iron forces them to to a degree, but their cling is gently, and just a little bit of pulling separates them into individual clusters of french fry nuggets.
They're sort of the monkey bread of the potato world. Or maybe the monkey bread of the waffle world. Or perhaps the monkey bread of that section of the Venn Diagram where waffles and potatoes overlap.
Don't you wish all waffle fries did this?
About the author: J. Kenji Lopez-Alt is the Chief Creative Officer of Serious Eats where he likes to explore the science of home cooking in his weekly column The Food Lab. You can follow him at @thefoodlab on Twitter, or at The Food Lab on Facebook.