The Science Behind Which Potatoes Work for Different Types of Cooking

Published online: Oct 13, 2020 Articles Julia Bayly
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Source: Bangor Daily News

Baked, mashed, roasted, boiled or pan-fried, there’s a lot more that goes into what makes a potato taste the way it does than preparation and condiments.

“A lot of things affect the flavor of individual potato varieties,” said Greg Porter, professor of agronomy with the University of Maine. “There is climate, temperatures, moisture and day length all affect the physiology of the plant and the type of materials that end up in the tuber, but the most important factor in taste is variety.”

Those environmental factors influence the amount of sugars and starches the potato is able to store and help give each variety its own unique flavor and texture.

Porter would know. He’s spent decades carefully selecting and breeding different tuber traits and characteristics to develop new varieties such as the Caribou Russet, introduced to markets last March.

“People tend to like, and are loyal to, certain varieties,” Porter said. “They are used to them and used to the texture, taste and aroma of that variety, and it’s a combination of all those things that factor in to what makes one person like one potato over another.”

Within each variety are specific amounts of stored sugars and starches, according to Mary Camire, professor of food science and human nutrition at the University of Maine, in addition to specific phenolic compounds.

“Potatoes that are low in moisture but with high sugar and starch contents like russets or Yukon golds are better baked, mashed, fried or roasted,” Camire said. “More waxy potatoes like round reds have a higher moisture content but less starch and will hold their shape better when cooked, so work better in salads or soups.”

At the cellular level, it is the phenolic compounds found primarily in the potatoes’ skin that add a great deal of the tubers’ flavors.

Growing conditions from one season to another affect the amount of phenolic compounds and sugars in potatoes, Porter said.

This growing season, Porter said, started off cool and dry followed by a long, hot stretch of weather and finally some rain toward the end of the growing cycle.

“That combination probably resulted in delayed tuber growth and the development of more sugars,” he said. “There are a high number of phenolic compounds in the potatoes [and] they are affected by the conditions, [and] if people are saying potatoes taste different this year from last year, that could be why.”

“Phenolic compounds also help the potato from getting eaten by some pests,” Porter said. “You find these compounds more in the peels than in the flesh of the tuber, and they are what cause the potato to turn green and bitter if they get too much light exposure.”

Which is why it’s a good idea to store potatoes in the dark, Porter said.

Potatoes like to be cool, Camire said, but not too cold.

“Storing them in a refrigerator is too cold, and those temperatures cause the starches in the tuber to turn into sugars,” she said. “That can create an overly sweet potato flavor.”

At the same time, cooks like a certain amount of those sugars to form as they help create a crisp, brown crust when frying potatoes.

Potatoes, according to information supplied by the Maine Potato Board, are low in calories — 100 calories in an average size tuber — and low in cholesterol.

They are excellent sources of vitamins C, B6, fiber and potassium.