Why did my potato salad go dry, claggy or greasy?
The variety, the temperature at which you dress it and the acid step almost nobody does — the three things that separate a good potato salad from a bowl of paste.
- Difficulty
- beginner
- Time
- 15 min
- Read
- 3 min
Short answer
Use waxy potatoes, dress them while still warm with something acidic — vinegar or lemon and a little oil — and only add mayonnaise once they are cool. Warm potatoes absorb the acid and the seasoning; warm mayonnaise splits and goes greasy, and floury potatoes crumble into the dressing and turn it to paste.
Almost every potato salad fault traces back to doing all the dressing in one go at the wrong temperature, with the wrong potato. Splitting it into two stages fixes nearly everything.
Step by step
- Buy waxy potatoes and cook them whole.Charlotte, Anya, Jersey Royals, Nicola or anything sold as salad potatoes. Cook them whole and unpeeled in salted water from cold — whole and skin-on keeps water out and flavour in, and skins slip off easily afterwards if you want them off.
- Simmer gently and stop at just-tender.A rolling boil bashes the pieces about. Test with a skewer at the centre of the largest; slight resistance is right. Drain and let them steam for a minute.
- Cut while warm and dress immediately with acid and oil.Cut into the size you want, tip into a wide bowl and pour over a couple of tablespoons of white wine vinegar or lemon juice with a slosh of oil, plus salt and plenty of black pepper. Warm potato is porous and drinks it up; cold potato does not. This step alone accounts for most of the difference between a bland and a seasoned potato salad.
- Cool completely before the mayonnaise.Spread on a tray to cool quickly. Mayonnaise added to warm potatoes thins, separates and pools as oil at the bottom of the bowl. This is the greasy potato salad problem in its entirety.
- Loosen the mayonnaise before folding it in.Slacken it with a spoonful of yoghurt, crème fraîche, soured cream or just a little of the potato cooking water or more vinegar. Neat mayonnaise straight from the jar is far too stiff and it drags the potatoes apart as you stir, which is what makes a claggy salad.
- Fold, do not stir.A wide bowl, a spatula, and a lifting motion from the bottom. Every extra stir breaks more potato surface into the dressing and thickens it towards paste.
- Add the fresh things last and season again.Spring onion, chives, dill, capers, cornichons, celery or soft-boiled egg. Then taste. Cold food needs more salt and more acid than it seems to when you are tasting at room temperature.
Tips
- A German-style potato salad — warm, with stock, mustard, vinegar and oil and no mayonnaise at all — sidesteps every mayonnaise problem and travels better in warm weather.
- Make it the day before if you like, but hold back a little dressing to refresh it, because chilled potato absorbs more overnight.
- Potato salad is a mayonnaise-based dish kept cold. Take it out of the fridge shortly before serving and put leftovers back promptly, especially outdoors in summer.
If it doesn't work
Thick, pasty, dressing has disappeared into the potatoes
Cause: Floury potatoes, or over-stirring, or mayonnaise too stiff — Fix: Loosen with a spoonful of yoghurt or crème fraîche and a squeeze of lemon. Fold gently. Next time use waxy potatoes and slacken the mayonnaise first.
Oily film at the bottom of the bowl
Cause: Mayonnaise added while the potatoes were still warm, so the emulsion broke — Fix: Drain the free oil off and fold in fresh loosened mayonnaise once cold. Cool completely next time.
Tastes of nothing
Cause: Seasoned only at the mayonnaise stage, when the potatoes were cold and closed — Fix: Add vinegar and salt directly to the potatoes; it will help even now. Next time dress with acid while warm.
Watery after a few hours in the fridge
Cause: Potatoes not drained and dried, or watery additions like cucumber — Fix: Drain, refresh with a little extra dressing, and keep high-water vegetables out.
Questions people ask
Can I use leftover boiled potatoes?
Yes, but you lose the warm-dressing step, so compensate with a more acidic dressing and season harder.
Skins on or off?
On, for new and salad potatoes — flavour, texture and less work. Off for larger maincrop potatoes where the skin is thick.