This is the time of year when we're all thinking about soothing our weather-weary bones with some old-fashioned, just-like-mom-would-make comfort food.
When it comes to comfort, no dish says "sit down and warm up" better than a buttery bowl of mashed potatoes.
But if you think that making the perfect bowl of mashers is as simple as boiling potatoes and stirring in some butter and milk, think again. There's science behind every spud.
Farmers, food scientists and chefs have devoted years of research to how to make perfect mashed potatoes. But even after all that study, personal preference will always be a factor.
So how do you like your mashed potatoes, fluffy or creamy?
Michelin-starred French chef Joel Robuchon introduced Americans to potatoes so creamy and laden with butter that they spread across the plate in a soft yellow mass. It's a style the French would refer to as pommes puree, in which the potatoes are passed through a food mill and combined with half their weight in butter.
This rich puree is to the extreme of what most of Americans think of as creamy mashed potatoes, and creamy potatoes can be achieved without a pound of butter.
But there is a science to creating the perfect mashed potatoes.
Select potatoes with care
The starch content of potatoes plays a big role in determining how mashed potatoes will turn out. Two of the preferred varieties for making mashed potatoes are russets or baking potatoes, and yellow potatoes.
When boiled, high-starch russets become dry and crumbly. Their flesh will soak up copious amounts of melted butter and cream, making them a good choice.
Yellow potatoes, such as the Yukon Gold variety, have a dense texture that many chefs prize for making mashed potatoes. They aren't as starchy as russets, but will produce a creamy finished product.
Save waxy red-skinned potatoes, such as the Red Bliss variety, for making rustic smashed potatoes with the skins on.
Peel, cube or cook whole?
Chefs disagree on whether to peel and cut potatoes before cooking them.
The editors of Cook's Illustrated magazine, in their book Cook's Illustrated: The Science of Good Cooking, maintain that potatoes cut into chunks before cooking can absorb too much water and have a soggy texture and washed-out flavor.
However, when potatoes are cooked whole they sometimes produce inconsistent results. Potatoes, particularly larger ones, can be bursting their skins on the outside while their centers are still hard.
Choose the method that works best for you, but use care to not overcook cubed potatoes or undercook whole ones.
Drain well and mash
Drain potatoes well and return them to their warm pot. Place over low heat to further dry them out, making them thirsty for butter and cream.
Every cook has a preferred masher. For fluffier potatoes, use a potato ricer; for creamier, a food mill; and for chunky with a few lumps left in, a potato masher.
Never use a food processor or blender, which will turn potatoes into gluey paste. Some purists will eschew an electric hand mixer as well, but others believe it produces a fluffy, whipped texture.
If using a hand mixer, take care not to overmix the potatoes. Consider putting them through a ricer first, then incorporating the butter and cream with a hand mixer to fluff them up.
Add butter and cream
A good rule of thumb is one stick of butter for every 2 pounds of potatoes. Melt the butter and add it first. As The Science of Good Cooking explains, the melted butter will coat the starch molecules with fat, which will keep them from reacting with the water in the milk or cream, which can turn the potatoes gluey.
Whole milk, half-and-half or heavy cream can all be used, up to 1 cup depending on your desired final consistency. Always heat the milk first to keep the potatoes from turning cold and stiff before serving.
Alton Brown's Creamy Mashed Potatoes
Makes 4 to 6 servings.
2 lbs. Yukon Gold potatoes
1/2 cup heavy cream
4 oz. (1 stick) unsalted butter, cut into pieces
1 tsp. kosher salt
1/4 tsp. freshly ground black pepper
Peel the potatoes and cut into uniform 1/2-inch pieces. Place into a 4-quart saucepan and cover with cold water by at least 1 inch. Cover, set over high heat and bring to a boil. Once boiling, remove the lid, decrease the heat to maintain a simmer and cook until the potatoes can easily be crushed with a pair of tongs, approximately 15 to 20 minutes. Drain in a colander.
Put the cream, butter, salt and pepper into the now empty 4-quart saucepan and place back over the heat until the butter has melted. Remove from the heat and set a food mill, fitted with the smallest die, on top of the pot. Add 1 cup of potatoes at a time to the mill. Once all of the potatoes have passed through the mill, stir to combine. Taste and adjust the seasoning, if necessary. Serve immediately.
Classical Mashed Potatoes
Makes 4 servings.
2 lbs. russet potatoes
8 tbsp. unsalted butter, melted
1 cup half-and-half, warmed
Salt and pepper, to taste
Place potatoes in a large saucepan and add cold water to cover by 1 inch. Bring to a boil over high heat, reduce heat to medium-low, and simmer until potatoes are just tender and a paring knife can be slipped in and out of potatoes with little resistance, 20 to 30 minutes. Drain.
Set ricer or food mill over now-empty saucepan. Using a pot holder to hold potatoes and paring knife, peel skins from potatoes. Working in batches, cut peeled potatoes into large chunks and press or mill into saucepan.
Stir in butter until incorporated. Gently whisk in half-and-half, add 1 1/2 teaspoons salt and season with pepper to taste. Serve.
-- "Cook's Illustrated: The Science of Good Cooking "
Joel Robuchon-style Pommes Puree
2 lbs. Yukon Gold potatoes
1 tbsp. salt
3/4 to 1 cup whole milk
2 sticks unsalted butter, diced and kept well chilled until used (see note)
Salt and pepper, to taste
Put the potatoes in a saucepan, cover with cold water by 1 inch. Add 1 tablespoon salt. Bring to a simmer, cover, and cook until a knife slips in and out of the potatoes easily and cleanly, about 25 minutes.
Drain the potatoes and peel them. Put them through a food mill fitted with its finest disk. Return milled potatoes to a saucepan. Place pan over medium heat and turn with a spatula to dry out the moisture in the potatoes.
In a small saucepan, add the milk and bring to a boil.
Turn the heat under the potatoes to low and incorporate the well-chilled butter bit by bit, stirring vigorously until potatoes are creamy. Pour in a cup of the hot milk and stir until absorbed. Add up to 1 cup additional hot milk until it has been absorbed and finished potatoes are smooth and silky. Turn off the heat and season with salt and pepper.
Makes 6 servings.
Note: Robuchon's original recipe had a ratio of 2 pounds of potatoes to 1 pound of butter. This recipe is less rich at 2 pounds of potatoes to 1/2 pound of butter.
-- Adapted from multiple sources