An Eye-Opening Look at Potatoes

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To the uninitiated, one potato may seem as good as another. But experienced cooks know that all potatoes are not all-purpose. Some are better for frying, others more suitable for salads. As with so many things, it may come down to chemistry.

“There are hundreds of different breeds of potatoes, and it turns out that beneath that yellow or brown or purple or red skin, they have quite different chemistries,” the BBC noted in a recent examination of the “humble spud.”

A few takeaways from the British broadcaster’s in-depth potato report:

1: Potatoes may be split into two categories. “Mealy” potatoes, such as purple potatoes and russets, are dry, fluffy, thick-skinned and starchy — about 22 percent starch by weight, according to research cited by the BBC. “Waxy” potatoes, like red and new potatoes, are moist and lower in starch (around 16 percent starch by weight), with thin skin and smooth flesh.

2: Mealy potatoes are perfect for mashing, baking and frying. Because they don’t contain much water, the BBC explains, “when their flesh hits hot oil, much of the water boils off before a skin forms on the surface, leaving just enough inside to gently steam” the inside of a fry. The starch molecules and thick skin help them form a skin without getting soggy.

3: Waxy potatoes are better bets for sauteing and boiling. Because they are moist, they tend to get droopy and soggy when fried, but they keep their shape better after they are cooked and so are excellent choices for salads.

Examined under a microscope, cooked mealy and waxy potatoes appear to differ. The starch molecules in mealy spuds form clumps and absorb water, creating the impression of graininess. Those in waxy potatoes retain their structural integrity and leave the water as is. That may be because the starches in mealy potatoes begin to break down in lower heat than waxy varieties, the BBC notes, directing those who wish to learn more about potato chemistry to this paper.

Check out some great Food Network potato recipes here.

Photo courtesy of iStock

Amy Reiter is a writer and editor based in New York. A regular contributor to The Los Angeles Times, she has also written for The New York Times, The Washington Post, Glamour, Marie Claire, The Daily Beast and Wine Spectator, among others, as well as for Salon, where she was a longtime editor and senior writer. In addition to contributing to Healthy Eats, she blogs for Food Network’s FN Dish.