Nobody enjoys wasting food, but when it comes to grabbing a doggie bag for fries, many diners opt to pass. After all, everyone knows that it's impossible to reheat french fries and make them crispy -- or is it?
When using a microwave, making reheated fries crispy is impossible. The science behind microwaves -- and leftovers -- illuminates why no tricks or hacks will produce that mouthwatering crunch we love about french fries. However, don't lose hope: To satisfy that fry craving, a batch of microwaved fresh shoestring fries just might do the trick.
Microwaves and Leftover Fried Foods
Microwaves heat food by radiation, channeling heat directly to the molecules of food: This is the same method the sun uses to warm your skin. Inside the microwave waves, magnetism and electricity oscillate at blazing-fast speeds -- 186,000 miles per second, to be precise -- bouncing erratically off the metal walls inside. These walls repel the waves of energy by reflecting them; the food inside can't reflect and the waves travel right through them. Every time these waves pass through your food, they cause the molecules in the food to vibrate wildly. The friction caused by these tiny but frantic vibrations heats the molecules, and subsequently, your lunch.
Now let's look at the nature of leftover french fries, and why the molecule dance party inspired by the microwave can't give back the crispy texture we crave. When you think about fried foods, you don't necessarily consider the water content, but it turns out that it's actually a pretty big deal to achieving crunch.
Crispiness is partially due to the hardened outside of the fried item, but much of our perception of "crisp" comes from the contrast in texture between soft and pillowy insides, and firm outsides. When a deep-fried food cools, that moisture from the inside migrates to the outside of the food, eliminating contrast and waterlogging the item. This same effect is not unique to fried foods either: Salads get limp and pastas get gummy due to the same molecular changes that occur when food stops cooking and starts sitting.
Because the heat from the microwave doesn't seal the outer layer of once-fried foods like the original bath in boiling oil did, it simply heats the water sitting on the surface of the fries as well as the water inside. Voila: soggy -- albeit rewarmed -- french fries.
To Do or Fry
There is one method that will turn raw potato into serious crispiness and deliver a delicious fry. The key is to keep the width of your fries very, very thin. By using a "spiralizer," you can peel away translucent strips of potato and transform them into crispy shoestring fries.
Step 1: Use the spiralizer.
Following the spiralizer's instructions, peel a potato into thin strips.
Step 2: Soak the fries.
Put the spiralized potato ribbons immediately into cold water. Let them soak for a few moments, then rinse them until the water rinses clear.
Step 3: Dry the fries.
Pat dry with paper towels or dishcloths, or use a salad spinner.
Step 4: Plate the fries.
As many as can fit on a plate, and in a single layer -- don't pile them -- place the dried potato ribbons. Season them with salt, and add any other flavorings you are in the mood for. Parmesan, garlic powder, chipotle or cayenne are great possibilities.
Step 5: Microwave.
On 100 percent power, microwave the fries for 3 minutes. Flip the ribbons and microwave at 50 percent for another 3 minutes.
Step 6: Remove and let cool.
As the fries cool, they'll crisp up more. Microwave all of the shoestring fries in batches, and add them to a bowl. Serve immediately, with your favorite condiments.
The microwave is a marvelous tool to get to hot foods faster: Now the same can be said of a fry craving as well.