Place potatoes into a large pot and cover with salted water; bring to a boil. Reduce heat to medium-low and simmer until potatoes are tender and split open, about 20 minutes. Drain and return potatoes to pot.
Mash potatoes with butter, nutmeg, and salt using a potato masher or fork until well incorporated; stir in sour cream until mashed potatoes are creamy.
Tips & Tricks
Slow Cooker Mashed Potatoes
See how to make creamy mashed potatoes in the Crockpot.
Mascarpone Mashed Potatoes
See how to make amazing make-ahead mashers with mascarpone cheese.