Starchy, waxy and all-purpose potatoes, which to use for what, and how to boil, mash, roast and bake them.

Starchy, waxy or in between

Starchy

Examples:
Russet, Idaho, Maris Piper
Texture:
Fluffy, dry, falls apart
Best for:
Baked potatoes, fries, fluffy mash

All-purpose

Examples:
Yukon Gold, white
Texture:
Creamy, holds its shape fairly well
Best for:
Mash, roasting, gratins, nearly anything

Waxy

Examples:
Red, fingerling, new potatoes
Texture:
Firm, holds its shape
Best for:
Potato salad, boiling, soups, roasting whole

Boiling and mashing

  1. Cut potatoes into even chunks and put them in a pot of cold, well-salted water. Starting cold cooks them evenly to the middle.
  2. Bring to a boil, then simmer until a knife slides in with no resistance, about 15–20 minutes for chunks.
  3. Drain well and let them steam dry in the pot for a minute or two.
  4. For mash, warm the butter and milk or cream before adding, and use a masher or ricer. A blender or food processor makes them gluey.

Crisp roast potatoes

  1. Cut into chunks and parboil in salted water for about 8 minutes, until the edges just soften.
  2. Drain and shake them in the pot to rough up the surfaces: the fluffy edges are what crisp.
  3. Toss with plenty of oil or fat on a preheated sheet pan and roast at 425°F (220°C) for 35–45 minutes, turning once, until deep golden.

Short on time? Skip the parboil: cut smaller, toss in oil and salt, and roast at the same temperature, turning once.

Baked potatoes

Scrub russets, prick them a few times, rub with oil and salt, and bake directly on the rack at 400–425°F (200–220°C) for 45–60 minutes, until a knife slides in easily. Skip the foil if you want crisp skin.

Storing

Keep potatoes somewhere cool, dark and dry, not in the fridge (cold turns their starch to sugar) and away from onions. Cut off green patches and sprouts before cooking: the green parts contain solanine, which is bitter and can upset your stomach in quantity.