Buttermilk mashed potatoes

My SO loves mashed potatoes¹, and some version of them has been included in many of our holiday meals to date. However, while we've posted recipes for variants on mashed potatoes, we've never posted our recipe for them. This omission is partly due to the fact that we don't have a recipe for mashed potatoes; we just throw everything together into a bowl, stir, and adjust the flavorings to suit our whims. Thus, to create this recipe we had to do something we hadn't done for years: we measured how much of each ingredient went into our latest batch of mashed potatoes.

This recipe is nothing special; it's just standard American mashed potatoes. Since we just whipped mashed these up tonight, it's this week's end-of-the-week recipe blogging post.

4 pounds potatoes (we typically use russet, but use whatever you prefer)
8 tablespoons (1 stick) salted butter
2 1/2 teaspoons kosher salt (or to taste; plus more for the potato water)
1/2 teaspoon ground black pepper
1/4 cup sour cream
3/4 cup buttermilk

0. Get a large pot of water heating on the stove; we add 1 tablespoon of kosher salt to the water (~6 quarts of water).
1. Wash the potatoes (we scrub them under running water), peel off any green bits of skin, and cut out any bad spots. Leave as much of the skin on as possible, and leave the potatoes whole.
2. Add the potatoes to the water, bring to a boil (if the pot isn't already boiling), and cook until the potatoes are tender (estimated 20-40 minutes, depending on potato size). Test the potatoes by lifting individual potatoes out of the pot with a cooking spoon and poking a paring knife or fork into the center of the potato; if the potato is tender throughout, the potatoes are done (the potato will fall easily off the knife). If your potatoes are uneven sizes, the smaller ones will cook faster; remove them to a strainer when finished and continue cooking the rest until they're done. Remove all potatoes to a strainer when completely cooked.
3. Once drained, put all the hot potatoes into a large bowl and add the butter, salt, and pepper. Mash with a potato masher; continue mashing until potatoes are at the desired level of lumpiness/mashedness. We like to leave ours a little chunky.
4. Stir in the remaining ingredients (sour cream and buttermilk) and mix until well combined. But don't overmix them, as that can make them gluey.
5. Taste the potatoes and adjust the seasonings.

Notes:

Mashed potatoes are incredibly flexible, so adjust this recipe to your liking. If you want them creamier, add more liquid (and/or fat); if you want them butterier, add more butter; if you don't like skins, remove the skins before cooking (this will likely lead to soggy potatoes, however); and if you've got a low tolerance for salt, lower the salt level. That said, don't try to make these with very low levels of salt or fat; both are critical to the flavor of good mashed potatoes.

The buttermilk makes the potatoes tangy, but you can make them with regular milk instead. If you're using regular milk, we'd suggest using about 1/2 cup milk and about 1/2 cup sour cream instead of the amounts listed above.

Some people claim that mashed potatoes don't reheat well; we say "bah" to that. We always make pounds upon pounds of mashed potatoes at a time, and enjoy the leftovers for days afterwards. We just reheat them in the microwave.

If you want a more extravagant meal, put a dollop of butter on each serving of potatoes.

To make wasabi mashed potatoes we add ~1 tablespoon pre-mixed wasabi paste in with the final ingredients. We've previously posted our recipe for cheddar cheese and bacon mashed potatoes. And, if you're looking for something really different, try our mashed turnips and potatoes recipe.

¹ Actually, my SO just loves potatoes; my SO's love of mashed potatoes is a subset of this broader love.