Chef John's Ultimate Mashed Potatoes

Instructions

• Peel potatoes and cut into quarters. Transfer to a bowl of cold water and rinse to remove starch. Drain and transfer to a pot of cold water. Very generously salt the water and bring to a boil over high heat. Reduce heat and simmer until potatoes are soft and the tip of a knife goes in easily, 20 to 25 minutes.
• While the potatoes are cooking, cut butter in chunks and let come to room temperature.
• Drain potatoes thoroughly and return to the pot. Set over medium-low heat and mash with a potato masher until potatoes. Season with salt and pepper and add ¼ of the softened butter chunks. Mash until butter just about disappears.
• Add another 1/4 of the butter and mix with a wire whisk until it just about disappears. Whisk in the remaining butter in 2 additions as before; potatoes will be light and creamy after all the butter has been mixed in.
• Whisk in hot milk until incorporated. Add cayenne and more salt if needed. Serve immediately.