Know Your Potatoes and Boiling
Cooking Skills: Potatoes 1
Chapter 1 · Know Your Potatoes and Boiling
Shopping list for this chapter
The basics
Not all potatoes are the same. The key difference is starch. A floury potato is full of starch, so it goes fluffy and falls apart when boiled; a waxy potato has less, so it stays firm. Using the wrong type is behind most potato disasters, such as watery mash or salad that turns to mush.
| Type | Starch and texture | Best for | Examples (UK) |
|---|---|---|---|
| Floury | High starch, dry, fluffy, breaks up when boiled | Mash, roast, baked, chips, gnocchi | Maris Piper, King Edward, Russet, Rooster |
| Waxy | Low starch, firm and moist, holds its shape | Boiling, salads, gratins, sauté | Charlotte, Jersey Royal, Anya, new potatoes |
| All-rounder | Somewhere between | Almost anything, a safe default | Desiree, Estima, Marfona, Wilja |
Packets often only say 'white potatoes' or 'baking potatoes'. Look for the variety name; if there isn't one, 'baking' usually means floury, and 'salad' or 'new' means waxy. A bag of all-rounders will manage most things.
The rules for boiling
- Start in cold water, salted, so the potato cooks through evenly.
- Cut to the same size so all the pieces finish together.
- Simmer, don't boil hard. A rolling boil knocks the outsides to mush before the middle is cooked.
- Test with a knife, not the clock. Timings vary with the potato.
- Drain and steam dry for a couple of minutes. Wet potatoes make wet mash and sad roasties.
- Boiling whole with the skin on keeps in more flavour and nutrients, and the skin peels off easily afterwards.
Try it
Boiled new potatoes with butter and mint
The simplest potato dish, and the one to get right first. Waxy potatoes hold their shape, so they are hard to ruin.
Ingredients (1 portion)
- 250 g new or waxy potatoes (e.g. Charlotte, Jersey Royal), scrubbed
- 1 tsp salt, for the water
- 10 g butter
- 1 tbsp chopped mint (or parsley)
- Cut the potatoes into pieces of roughly equal size (halve large ones). Leave the skins on.
- Put them in a pan, cover with cold water by 2 cm and add the salt. Bring to the boil, then lower to a gentle simmer.
- Cook for 12 to 15 minutes, until a knife slides in with no resistance but the potato does not fall apart.
- Drain, let them steam dry for 2 minutes in the colander, then toss with the butter and mint.
Steamed potatoes with chive yoghurt
Steaming keeps the potatoes out of the water, so they taste more of potato and stay fluffier. A lighter way to serve them.
Ingredients (1 portion)
- 250 g waxy or all-rounder potatoes, cut into even chunks
- 1 tbsp plain yoghurt
- 1 tbsp chopped chives
- 1 pinch salt and pepper
- Put 3 cm of water in a pan and bring it to the boil. Set a steamer basket or a colander over it, so the potatoes sit above the water.
- Add the potatoes, cover tightly, and steam for 18 to 22 minutes, until a knife slides in easily. Top up the water if it runs low.
- Mix the yoghurt, chives and seasoning. Spoon over the hot potatoes.
Crushed potatoes with olive oil and lemon
Boil small waxy potatoes, squash each one flat with a fork, and dress them while hot. The cracked surfaces soak up the oil.
Ingredients (2 portions)
- 300 g small waxy potatoes (new potatoes), scrubbed
- 1 tsp salt, for the water
- 2 tbsp extra-virgin olive oil
- ½ lemon, zest and a squeeze of juice
- 1 tbsp chopped parsley
- 1 pinch flaky salt and pepper
- Boil the potatoes whole in salted water, from cold, for 15 to 18 minutes until completely tender. Drain and steam dry for 2 minutes.
- Put them on a plate or board, and press each one with the back of a fork until it splits and flattens.
- Drizzle with the olive oil, lemon zest and juice, and scatter over the parsley and flaky salt. Eat warm.
Warm potatoes in mustard vinaigrette
Potatoes absorb a dressing best while hot. Mixing it with warm potatoes gives far more flavour than pouring it over cold ones (the experiment below proves it).
Ingredients (2 portions)
- 300 g waxy potatoes, cut into 2 cm chunks
- 1 tsp salt, for the water
- 1 tbsp olive oil
- 1 tbsp white wine vinegar or lemon juice
- 1 tsp wholegrain mustard
- 2 spring onions, sliced
- 1 tbsp chopped parsley
- 1 pinch salt and pepper
- Boil the potatoes from cold in salted water for 10 to 12 minutes, until just tender. Drain.
- Meanwhile whisk the oil, vinegar, mustard and seasoning in a bowl.
- Tip the hot potatoes into the dressing, add the spring onions and parsley and fold gently. Eat warm or at room temperature.
Experiments
Cold or hot start
Does it matter?
- Cut 400 g of potatoes into 3 cm chunks and split into two pans. Start one in cold water and the other in already boiling water, both salted and simmered gently.
- Test both with a knife every 3 minutes and compare the edges and the middles.
Look for: The hot-start chunks are usually softer or breaking on the outside while the middle is still firm. The cold start cooks more evenly.
Skin on or peeled
Where does the flavour go?
- Boil two equal batches of potatoes, one peeled and one in their skins, in the same amount of water.
- Weigh them before and after cooking, and taste both plain.
Look for: The skin-on potatoes are less waterlogged and taste more of potato. The peeled ones soak up water. (Peel waxy potatoes after boiling if you prefer.)
Whole or cut
Size and sogginess.
- Boil a few whole small potatoes and the same weight cut into 2 cm pieces.
- Compare the cooking times and the texture.
Look for: The cut pieces cook in half the time but take up more water and break more easily.
Salted or unsalted water
Season the water?
- Boil two batches, one with 1 teaspoon of salt per litre and one with none.
- Taste both plain.
Look for: The salted potato tastes seasoned all the way through. Salting after the cooking only seasons the surface.
Warm or cold dressing
When to dress a salad.
- Make the vinaigrette from the last recipe. Toss half the boiled potatoes in it while hot and half after they have cooled.
- Taste after 30 minutes.
Look for: The warm-dressed potatoes soak up the dressing and taste of it all the way through. The cold-dressed ones taste of potato with dressing outside.
Tasting notes
| What I tried | Method or amount | What I saw | What I thought | Will I do it again? |
|---|---|---|---|---|
| Boiled new potatoes | ||||
| Steamed potatoes | ||||
| Crushed potatoes | ||||
| Warm vinaigrette potatoes | ||||
| Cold vs hot start | ||||
| Skin on vs peeled | ||||
| Whole vs cut | ||||
| Salted vs unsalted | ||||
| Warm vs cold dressing |
Troubleshooting
| Problem | Likely cause | What to do |
|---|---|---|
| Potatoes fall apart | Floury type, or boiled too hard or too long | Use waxy potatoes for boiling; simmer; test early |
| Hard in the middle | Pieces too big or uneven, or hot start | Cut evenly; start from cold |
| Watery or bland | Not salted, or left to stand in water | Salt the water; drain at once and steam dry |
| Grey or dark | Peeled and left to stand | Keep peeled potatoes under cold water until cooking |
| Green patches or bitter taste | Light exposure when stored | Cut away green; throw away if green all over |
| Waterlogged salad | Dressed when cold, or cooked too long | Cook until just tender and dress while warm |
Cooked potatoes: cool them quickly (spread out, within 1 to 2 hours), keep them covered in the fridge, and eat them within 2 days. Reheat until steaming hot all the way through, and only once. (This is the general chilled-leftovers advice relayed by local-authority food-safety pages; unlike rice, potatoes have no special rule of their own, but they are starchy, so they are treated with the same care.)
- I can tell floury from waxy potatoes.
- I can boil potatoes evenly and drain them well.
- I know why I start in cold water and salt it.
- I can steam potatoes and crush them.
- I know how to store potatoes safely.