Boiled potatoes sound simple until half the pan is soft and crumbling while the largest pieces are still firm. The solution is to choose a suitable potato, cut it evenly and keep the water at a controlled simmer rather than a fierce rolling boil.
The timing depends on whether you're cooking small new potatoes, larger peeled chunks or whole potatoes for a salad. For most home cooking, test the centre with the tip of a knife rather than depending on one number of minutes.
Choose the potato for the dish
Waxy varieties generally hold their shape better during boiling. They work well for potato salads and buttered new potatoes.
Floury varieties such as Maris Piper or King Edward soften readily and can make excellent mash, but they are more likely to break apart if boiled vigorously.
Look for firm sound potatoes without extensive green patches, rot or an unpleasant smell. Remove dirt before cutting and discard any with major spoilage.
If you're making mash, you can be less concerned about holding perfect shapes. For a salad, selecting similarly sized waxy potatoes matters more.
Should you peel potatoes before boiling?
You can boil potatoes peeled or unpeeled. Young new potatoes often have thin skins that are pleasant to eat after washing.
For very smooth mash, peeling first can save time later. For a salad, boiling small potatoes with the skins on may help them retain their structure.
Wash the surfaces under running water, especially if the potatoes were stored with soil attached. Trim damaged areas as appropriate.
Use a stable chopping board and a sharp suitable knife. Large raw potatoes can be difficult to halve if the knife is blunt.
Cut pieces to a similar thickness
If you are boiling chunks, keep them relatively even. Small pieces cook far more quickly than whole large potatoes.
Cut large potatoes into halves or quarters as required, then check that the pieces are of similar thickness, not merely similar length.
For a bowl of buttered new potatoes, leave small ones whole and halve the much larger ones. This gives them a better chance of finishing together.
Don't spend ages trying to make perfect cubes. A consistent size matters more than whether the edges look decorative.
Start in cold water or boiling water?
For many ordinary boiled-potato recipes, placing the potatoes in a saucepan of cold water and bringing them up to heat together gives more even cooking.
Put the prepared potatoes in the pan and cover them with enough cold drinking water to submerge them. Add a little salt if appropriate.
Bring the pan to a boil, then reduce the heat so it simmers gently. The water should move around the potatoes without knocking them against each other constantly.
Some recipes deliberately start small pieces in boiling water. Follow the method you're making if it has a different purpose.
Why a gentle simmer is better
A fierce boil can break softening potato edges while leaving the middle firm. The cloudy water may contain starch and little fragments from damaged pieces.
Turn the heat down after the water reaches a boil. Keep enough movement to cook the potatoes, but don't let them bounce wildly.
Covering the pan partially may reduce energy use, but watch closely for foaming or boiling over. A starchy saucepan can rise suddenly, especially if it is too full.
Stir only if necessary. Constantly stirring boiling potato chunks can knock off their softened edges.
How long does boiling take?
Very small diced pieces can become tender fairly quickly, while large whole potatoes can require considerably longer. As a rough guide, many medium chunks take around fifteen to twenty minutes after heating, although variety and size can change that.
Begin testing early if the chunks are small. Insert a knife into one of the thickest pieces; it should slide in easily when the potato is ready.
For mash, a thoroughly tender piece is what you want. For a salad, stop before the edges fall apart and the potato becomes too soft to slice.
Don't increase the heat to maximum just to shorten the time. The outside may disintegrate before the centre is done.
Drain carefully and let the potatoes steam
Once tender, switch off the hob and drain the pan through a suitable colander. Be careful of steam and splashing hot water.
If you're serving buttered potatoes, return them to the warm empty pan briefly and let any surface moisture evaporate. Add butter, herbs or other dressing when they're no longer swimming in water.
For mash, steam-drying is especially valuable because extra liquid can produce a watery result later.
Avoid leaving drained potatoes exposed on a cold countertop for an extended time while the rest of dinner is being prepared.
Serving new potatoes simply
Small boiled new potatoes are pleasant with a little butter, parsley or chopped chives. Their flavour doesn't need a complicated sauce.
Try a squeeze of lemon or a spoonful of suitable yoghurt dressing if the rest of the meal is rich.
If you plan a warm potato salad, combine potatoes with dressing while they're warm enough to absorb flavour, then handle and chill appropriately.
Keep the seasoning light until you've tasted the potatoes. A strong dressing can obscure the delicate flavour of small new potatoes.
Boiling potatoes for mash
Choose a floury variety, cut into even chunks and cook until the centre is completely tender. Drain thoroughly and allow steam to escape.
Mash while they're still warm. A potato masher or ricer can give a smooth result without needing a food processor.
Avoid a blender, which can overwork potato starch and give the mash an unpleasant gluey texture.
Warm milk or butter can be folded in as needed, but the exact quantities depend on the potato and how rich you want the final dish.
What about boiling potatoes for freezing?
Good Food recommends part-cooking potatoes before freezing them for later use. Raw potatoes generally don't freeze with an attractive texture.
For freezer-ready pieces, stop cooking before they become fully soft, cool promptly and spread them on a tray so they freeze separately.
Pack into freezer-safe bags and label the date. When using them later, allow enough cooking time for the centre to become thoroughly hot.
A fully cooked potato can also be frozen in some preparations, but follow a method designed for mash, roasts or the dish you're making.
Fixing potatoes that have cooked unevenly
If some pieces are hard, leave those in the simmering water a little longer while removing any that are fully tender.
If everything is breaking apart, drain promptly. The pieces may still be useful for mash or soup, even if they're no longer suitable as neat buttered potatoes.
If the mash turns watery, let excess steam escape before adding more milk. Don't keep pouring cream into potatoes that were already overloaded with cooking water.
Once you've selected a potato and cut it evenly, boiling becomes a much more predictable method. Cook gently, test the largest piece and drain promptly.
Sources checked
Good Food: how to make mashed potatoes and Good Food: how to freeze cooked potatoes.