Light and fluffy yet rich and creamy, with just a hint of garlic, thyme, and tangy sour cream: These spuds are the mashed potatoes of our dreams.
Ingredients
4 pounds Yukon Gold potatoes, peeled, cut into 2" pieces
6 large garlic cloves, peeled
1 tablespoon plus 2 teaspoons kosher salt, divided, plus more
1 1/4 cups whole milk
4 thyme sprigs
3/4 cup (1 1/2 sticks) plus 2 tablespoons unsalted butter, divided
3/4 teaspoon freshly ground black pepper, plus more
1/2 cup sour cream
A potato ricer or food mill
Directions
Cover potatoes, garlic, and 1 Tbsp. salt with cold water in a large pot. Bring to a low boil, then reduce heat and simmer (do not boil) until potatoes are very tender when pierced with the tip of a paring knife but not falling apart, 20–25 minutes.
Meanwhile, heat milk, thyme, and 3/4 cup butter in a small pot over medium, stirring, until butter is melted. Remove from heat; set aside.
Drain potatoes and garlic; return to pot. Toss over low heat until moisture evaporates, 1–2 minutes. Using potato ricer or food mill, immediately press potatoes and garlic into a large bowl (do not let cool).
Discard thyme from milk mixture and gradually stir into potatoes, reserving about 1/2 cup if you plan to make in advance (see Do Ahead). Season with 2 tsp. salt and 3/4 tsp. pepper. Fold in sour cream and stir with a spoon until incorporated and very smooth (do not overmix or potatoes will become gummy). Taste and adjust seasonings. Serve topped with remaining 2 Tbsp. butter and more pepper.
Mashed potatoes can be made 2 hours ahead; cover and store at room temperature. Or chill, covered, up to 8 hours; reheat over medium with reserved 1/2 cup milk mixture.
