Potato Salad With Tomato Dressing — A Lighter Take on a Heavy Classic

A healthy potato salad without mayonnaise starts with swapping the dressing, not cutting it back. I first made this for a bank holiday barbecue when one guest couldn't eat eggs and another was watching their calorie intake, and honestly, nobody missed the mayo. The tomato dressing brings acidity that cuts through the starch, keeps the salad feeling light on a hot day, and pairs properly with anything you'd normally serve alongside a traditional potato salad. It also happens to be quicker to make because you're not faffing with emulsifying a cold sauce. What follows is the version I've settled on after a few goes — with real quantities, the timing that matters, and the practical detail you need if you're making it for a crowd.

Why the Mayonnaise Version Is So Heavy

A classic mayonnaise potato salad relies on egg yolk and oil as its base, which is why it tastes rich and coats the mouth. A standard tablespoon of full-fat mayonnaise contains roughly 100 calories and 11 grams of fat, according to the nutritional data published by the British Nutrition Foundation. When you're dressing half a kilogram of potatoes, the mayonnaise adds up fast — both in calories and in that heavy, cloying feeling that sits in your stomach after a barbecue.

The bigger problem is acidity. Mayonnaise is mildly acidic thanks to the vinegar or lemon juice in it, but it's diluted by all that fat. A tomato-based dressing, by contrast, brings a much sharper hit of acidity from the tomatoes themselves and from the vinegar you add. General cooking knowledge tells us that acidity is the single most effective tool for making starchy food taste lighter. It's the same reason people squeeze lemon over chips, or why a proper vinaigrette transforms plain pasta into something that doesn't feel heavy. Swap the mayo for a tomato dressing and you're replacing fat with acid as the dominant flavour, which changes the character of the salad entirely without making it taste like it's missing something.

Choosing the Right Potato

Waxy potatoes are the only sensible choice for a dressed salad, because they hold their shape once cooked. Varieties like Charlotte, Jersey Royal and other new potatoes have a firm, waxy texture that stays intact when you toss them. If you reach for floury potatoes — Maris Piper, King Edward, or the sort you'd use for mash or roasties — they'll crumble the moment you start mixing. You'll end up with a broken, stodgy mess that sits in a lump rather than forming distinct, coated pieces.

This distinction matters even more with a tomato dressing than with mayonnaise. Mayonnaise is thick enough to hold crumbled potato together into something that at least looks cohesive. A thin tomato dressing can't do that. If the potatoes break, the dressing pools at the bottom of the bowl and you get dry, naked lumps of potato on top and a watery puddle underneath. Use waxy varieties and cook them until they're just tender — a knife should slide in with slight resistance — and they'll take the dressing beautifully without falling apart. If you can only get floury potatoes, undercook them slightly and handle them with extreme care, but honestly, it's worth seeking out a waxy variety. Charlotte potatoes are widely available in UK supermarkets all year round and they're reliable.

The Tomato Dressing

The dressing for a healthy potato salad without mayonnaise should be punchy enough to stand up to the potatoes without overwhelming them. Here's the version that works consistently.

You'll need 400 grams of ripe tomatoes, 45 millilitres of extra-virgin olive oil, 30 millilitres of red wine vinegar, 5 grams of caster sugar, a teaspoon of Dijon mustard, a small clove of garlic (finely grated), a small handful of fresh basil (about 10 grams, roughly torn), and fine salt and black pepper to taste.

The sugar isn't there to make it sweet — it's there to balance the acidity of the tomatoes and vinegar so the dressing tastes round rather than sharp. The Dijon mustard acts as an emulsifier, helping the oil and vinegar stay combined rather than separating into layers. If your tomatoes aren't particularly ripe, add an extra teaspoon of sugar and a squeeze of lemon juice. The basil goes in last, just before dressing the potatoes, so it stays fresh and green rather than turning dark and bruised. This quantity of dressing is enough for 800 grams of cooked potatoes, which serves six to eight as a side dish.

The Method

Start by putting 800 grams of waxy potatoes — Charlotte or Jersey Royals are your best bet — into a large pan of cold, salted water. Bring it to the boil, then turn the heat down to a steady simmer and cook for 18 to 22 minutes, depending on the size of your potatoes. They're done when a sharp knife slides through with only slight resistance. Drain them and let them steam in the colander for two minutes.

While the potatoes are still warm, cut them into halves or thick slices — roughly 1 centimetre thick — and tip them into a large bowl. This is the step that matters most: dressing warm potatoes is essential because they absorb the dressing as they cool, which is why a warm-dressed salad tastes seasoned all the way through, whereas a cold-dressed one tastes of dressing sitting on top. Pour the tomato dressing over the warm potatoes, toss gently with a large spoon, and leave the salad to cool to room temperature. The potatoes will drink in the dressing as they sit, so give it another gentle toss after 10 minutes. Season with more salt and pepper if needed. Scatter the torn basil over the top just before serving.

Making It Ahead and Taking It to a Barbecue

You can make this salad the day before you need it. Dress the potatoes while they're warm as described, let them cool completely, then cover the bowl and refrigerate. The flavours will develop overnight and the salad will taste even better than it does fresh. Give it a gentle toss and check the seasoning before you leave the house.

For transport, a sealed container kept in a cool bag with an ice pack is the practical approach. General cooking knowledge and food safety guidance from the UK Food Standards Agency make clear that a mayonnaise-free salad is more forgiving in the sun because there are no raw eggs involved. That said, no potato salad — with or without mayonnaise — should sit out for hours in the heat. If it's a hot day and the salad's been on the table for more than two hours, it's sensible to put it back in the fridge or a cool bag. This isn't about being alarmist; it's about common sense. If you're at a barbecue and the salad's been sitting in full sun on a 28-degree day, use your judgement and pop it back in the shade or inside.

Variations That Work

You can adjust this base recipe without losing what makes it work. Try adding 100 grams of finely sliced radishes for crunch, or a handful of pitted black olives for saltiness. A tablespoon of capers, rinsed and roughly chopped, brings a briny punch that plays well against the tomatoes. If you want more protein to turn it into a light lunch, stir through two drained 400-gram tins of butter beans or a couple of flaked tins of tuna after the salad has cooled.

For a smokier flavour that suits barbecued food particularly well, swap the red wine vinegar for smoked paprika-spiked sherry vinegar — use the same quantity of vinegar but add half a teaspoon of smoked paprika to the dressing. Fresh dill or flat-leaf parsley can replace basil if that's what you've got. The principle stays the same: dress warm, keep the dressing sharp, and let the potatoes do the absorbing.

Frequently asked questions

Which potatoes should I use?

Waxy varieties like Charlotte, Jersey Royal or other new potatoes. They hold their shape when dressed. Floury potatoes such as Maris Piper or King Edward will crumble into the dressing and leave you with a broken, stodgy mess. Charlotte potatoes are widely available in UK supermarkets year-round and are the most reliable option.

Can I make it the day before?

Yes, and it actually improves. Dress the warm potatoes, let them cool, then refrigerate in a sealed container. The flavours develop overnight. Toss gently and taste for seasoning before serving — you may want a little more salt or a splash of vinegar to wake it up.

Does it keep in the sun at a barbecue?

It's more forgiving than a mayonnaise-based salad because there are no raw eggs. The UK Food Standards Agency advises that no food should sit out at room temperature for more than two hours. On a very hot day, err on the side of caution and put it back in a cool bag or the fridge after an hour and a half.

Can I use tinned tomatoes instead of fresh?

You can, but drain them very well first and chop them finely. Tinned tomatoes carry more liquid and a cooked flavour that's different from the brightness of fresh ripe tomatoes. If you do use tinned, choose whole plum tomatoes and crush them by hand, then drain off the excess juice. Add an extra squeeze of lemon to compensate for the lower acidity.

What should I serve it with?

It pairs naturally with anything off the barbecue — grilled chicken, sausages, halloumi or vegetable skewers. It also works as part of a cold buffet alongside green salads, crusty bread and a simple coleslaw. Because the dressing is lighter than mayonnaise, it doesn't compete with rich or smoky main dishes the way a traditional potato salad sometimes can.