One spectrum explains almost everything
Potatoes seem interchangeable, a pile of brown lumps in a bin, but they’re not, and almost every potato dish that goes wrong goes wrong because the cook grabbed the wrong type. The key is a single spectrum running from starchy to waxy, and where a variety falls on it determines what it can do.
Starchy potatoes, russets and Idaho bakers, are low in moisture and high in starch. When they cook, those starch granules swell and separate, giving a light, fluffy, dry interior. That’s exactly what you want for a baked potato, for fluffy mash, and for fries with a crisp shell, but it’s why a russet disintegrates into mush if you try to boil it for a salad. Waxy potatoes, red potatoes, new potatoes, and fingerlings, are the opposite: high moisture, low starch, with more of a sticky, fine-grained starch that holds the cells together. They keep their shape through boiling, so they’re the right choice for potato salad, for gratins, and for roasting in chunks that need to stay intact. All-purpose potatoes, the yellow Yukon Gold being the famous one, sit in the middle and are the sensible default when a recipe doesn’t specify: good mash, respectable roast, sturdy enough to boil.
Internalize that one distinction, starchy for fluffy-and-crisp, waxy for holds-its-shape, all-purpose when unsure, and most potato problems simply stop happening.
Storage, and the fridge trap
Potatoes want a cool, dark, ventilated spot, somewhere around 45–55°F (7–13°C), in paper or an open basket rather than a sealed plastic bag that traps moisture. What they don’t want is the refrigerator. It’s a surprisingly common mistake with a real consequence: cold temperatures convert the potato’s starch into sugar. That makes raw potatoes taste oddly sweet, and worse, the extra sugar causes them to brown too fast and produce more acrylamide (an undesirable compound formed when starchy foods are cooked hot) when you fry or roast them. Keep them out of the fridge and away from onions, which give off gases that hasten each other’s sprouting and spoilage.
While you’re at it, watch for green skin and sprouts. The green is just chlorophyll from light exposure, harmless in itself, but it flags a buildup of solanine, a bitter, mildly toxic compound the potato makes to defend itself. Trim away green areas and sprouts before cooking; toss any potato that’s extensively green, badly shriveled, or tastes bitter.
Technique unlocks texture
The same potato can be three different foods depending on how you handle it, and a few specific moves are what separate a good result from a great one. For crispy roast potatoes, the trick is to parboil cut chunks in well-salted water until just tender, then rough up their edges in the colander before roasting; that frayed, starch-coated surface is what crisps into the craggy, shattering edges everyone fights over. For fries and hash, do the reverse and rinse or soak the cut potatoes to wash off surface starch so they don’t glue together, then dry them completely so they crisp instead of steam. For mash, choose a starchy potato, start it in cold salted water, and handle it gently, rice it or mash by hand rather than whipping, because aggressive mixing ruptures the starch cells and turns the whole bowl gluey.
And in every case, salt the water. Potatoes are bland and starchy, and salt added only at the end just sits on the outside. Seasoning the cooking water lets the salt penetrate as they cook, which is the quiet reason restaurant potatoes taste seasoned all the way through. The per-method guides below cover roasting, baking, boiling, steaming, and air-frying in detail.