BRATTLEBORO — While there are many ways to cook a potato, there are also many ways to ruin it. As with most vegetables, over-cooking is the culprit.
Harold McGee, in On Food And Cooking, recommends boiling or steaming, as opposed to baking or roasting, for better nutrition, as the baked potato suffers from an especially precipitous drop in Vitamin C.
As McGee reports, when baking, the potato warms up very slowly, and the enzyme that destroys the nutrient has “more time to work. This is an excellent reason for the cook to put vegetables only into already boiling water, [because] up to 20 percent of the vitamin can be digested in one minute if it takes that long for the water to resume boiling.”
Steaming is the best choice, McGee says.
“Studies have shown that more than twice as much Vitamin C is retained in vegetables cooked in a small amount of water or steamed, compared to vegetables boiled in enough water to cover them completely.”
But, not everyone wants steamed potatoes, and not all varieties of potato have the best texture when cooked in this manner.
The easy way to determine which potato should be cooked in which way is by noting its texture.
Justin Nye, of Guilford's Circle Mountain Farm, says, “The starchy, floury potatoes are better for mashing.”
The high-starch potatoes, such as Russets, are also best for baking. They are not recommended for potato salad unless you like a mealy texture.
For potato salad, choose waxy potatoes, which have a lower starch content.
All-purpose potatoes, which have a medium-starch content, are best for roasting.
If nutrition is not your primary concern, French-frying potatoes is a delicious option, and as McGee writes, “several authoritative cookbooks concur in the view that in order to obtain the best French-fried potatoes, one should subject the potato strips to two cooking periods, first at a low temperature, around 325-degrees F, and then at a higher one, perhaps 370-degrees F. This odd-sounding technique does make sense.”
McGee describes the action the heat has on the starch in the potatoes on the surface and the interior, and the desire to have a crisp outside and a soft, flaky middle. Twice-frying does the trick.
In Belgium, where pommes frites originated -ۥ no, not France, despite the name - animal fats, especially from the horse and ox, were the preferred frying medium. Horse fat has a high amount of reactive, highly unsaturated fatty acids, thus providing savory notes to the potatoes.
Because American culture shirks from the notion of eating horses, horse fat is not readily available.
Thus, in descending order of success in texture and flavor, here are other fats one can use to French-fry potatoes: rendered fats from fowl (chicken, duck, or goose), beef tallow or lard, then vegetable oil.
As Mark Bittman noted in his October 21, 2013 New York Times column, “Deep Fried and Good for You,” since most deep-frying “is done at around 350 degrees, this whole notion that olive oil is inappropriate for frying is nonsense; it smokes at 375.”
Bittman does suggest using “pure” olive oil, rather than extra virgin, but only because the cost will likely be lower.
Regardless of how you cook them, Justin Nye warns: “Don't peel your potatoes! A lot of the nutrition is in the skin.”
Amy Frost, Nye's partner at Circle Mountain Farm, adds there's good nutrition “just under the skin, too.”
Both say, “That's why you should eat organic potatoes! You can eat the skin!”