There are two important keys to making good mashed potatoes. One, make sure the cooked potatoes are as dry as possible before you mash them. Two, don't overwhip the potatoes or they will turn out gluey.
In the classical culinary arts, the mark of good mashed potatoes is that they have a smooth and uniform consistency, with no lumps. In real life, a few lumps will give your mashed potatoes a rustic, handmade quality that is really wonderful. Also, classical mashed potatoes are always peeled, but leaving the peels on potatoes will add texture and color. It all depends on what you prefer.
While there is an infinite number of variations, this basic technique will help you make great mashed potatoes every time. It all starts with what kind of potatoes to use.
Choose the Right Potatoes
The best potatoes to use for making mashed potatoes are high-starch potatoes like Russet potatoes or medium-starch potatoes like Yukon Golds. These kinds of potatoes have the lowest moisture content, which is good because you want the potatoes to be as dry as possible.
Don't use red potatoes, white potatoes, or any other kind of waxy potatoes for making mashed potatoes. Plan on one good-sized potato per person. The steps that follow assume you are cooking four pounds of potatoes.
How to Make Mashed Potatoes:
- Scrub and peel the potatoes, then cut them into quarters. Cutting the potatoes into uniform-sized pieces means they will cook evenly.
- Bring a pot of salted water to a boil. Just boil enough water to cover the potatoes. Boiling more water than this will only make it take longer to come to a boil. Also, take 3 ounces of butter out of the fridge and let it get soft at room temperature.
- Add the potatoes to the boiling water and simmer, uncovered until they are fork-tender, which will take about 15 minutes, depending on how big the pieces are. While the potatoes are cooking, preheat your oven to 300 degrees Fahrenheit.
- Heat about half a cup of cream in a small saucepan, and keep it warm. In a separate saucepan, heat about a cup of whole milk. It's good to heat the milk and cream so that we don't cool down the potatoes too much. Note: You can make mashed potatoes using buttermilk and/or sour cream in place of the cream and milk. In this case, you don't want to heat either one. Just let them come to room temperature.
- When the potatoes are tender, drain them into a metal colander and shake off any excess water. Now, set the colander on a sheet pan or baking sheet and transfer it to the oven. Let the potatoes steam dry in the hot oven for 3 to 4 minutes.
- At this point, you can mash the potatoes with a potato masher, although a potato masher is bound to leave a few lumps. If you don't mind a few lumps, a potato masher will work fine. For a very smooth texture, use a potato ricer or a food mill. Both of these tools will get out all the lumps without overworking the starches.
- Add the softened butter and hot cream (or room temperature sour cream) and stir with a wooden spoon.
- Now stir in the hot milk (or room-temperature buttermilk) until the potatoes are moistened enough. You don't want them to be too stiff or too runny.
- Season to taste with Kosher salt and freshly ground white pepper.
- Finally, whisk by hand with a wire whisk for just a few seconds, until the mashed potatoes are fluffy. Don't overwhip. Serve right away.
Making Mashed Potatoes in a Stand Mixer
A stand mixer is a great tool for making mashed potatoes. Be careful not to overwhip the potatoes. After cooking the potatoes and drying them in the oven as described above, do the following:
- Attach the paddle attachment of your stand mixer and transfer the cooked potatoes to the bowl of the mixer. Mix on the lowest speed until most of the lumps are gone.
- Remove the paddle attachment and attach the whip attachment. Whip for a few seconds until the potatoes are fully puréed. Don't overwhip!
- Add the butter, cream, and milk as described above, mixing at the lowest speed until the mashed potatoes have the consistency you want. Then season to taste and give the potatoes one last quick whip, just to fluff them up. Serve right away.