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Science

Why You Shouldn't "Bake" Potatoes in the Microwave

Microwaving might be convenient, but it’s one of the worst ways to cook a starchy potato.
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Published Feb. 12, 2024.

Why You Shouldn't "Bake" Potatoes in the Microwave

Warm, fluffy baked potatoes are hands off, simple to make, and super versatile, working as a main course when they’re dolled-up or as a side for proteins or vegetables. The only drawback? It can take an hour to bake them. 

When you don’t have quite that much time to spare, you might turn to a common timesaving method: Microwaving the potatoes instead of baking them in an oven.

But when my colleague Lan Lam was developing her recipe for the Best Baked Potatoes, she discovered that the microwave is actually one of the worst approaches to cooking a russet potato. Here’s why.

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Why You Shouldn’t “Bake” Potatoes in the Microwave

In the oven, heat conducts in a gradual, orderly way through the potato, causing the starch granules to swell with free water contained within the spud’s cell walls. Eventually, these plumped up granules force the cells to separate into clumps that result in the texture we perceive as dry and fluffy.

But this happy circumstance doesn’t happen in the microwave.

Microwaves zap the food haphazardly, so that one part can get instantly very hot and a spot a millimeter away doesn't get hot at all. The rapid heating can cause the granules to burst, and release sticky, gelatinized starch.The result: A gluey potato that’s also often marred by hard nodules where the starch has crystallized. 

The Best Way to Bake a Potato

Lan tried plenty of timesaving tricks to determine the most efficient way to bake a potato, from the aforementioned microwave method to pressure cooking to roasting in a very hot oven. 

The best method by far, though, was simply baking the potato in a 450 degree oven to exactly 205 degrees (confirmed with an instant-read thermometer), which made the flesh dry and fluffy. At this oven temperature, the potatoes reached that target in about 45 minutes, and the exterior wasn’t overbrowned.

She also came up with a clever trick to ensure crispy skin: Brushing the potatoes with oil when they’re almost done baking. 

Many recipes tell you to oil a baked potato before baking. But Lan found doing so led to tough, sometimes leathery skins, as the oil limited evaporation. If you oil after the skin has already dried out, on the other hand, the skin essentially fries to a delicious crisp.

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