Should you keep tomatoes in the fridge?

The tomato-in-the-fridge argument is one of the few kitchen debates where science and Italian grandmothers broadly agree. Cold does something to a ripe tomato's flavour. The question is when that matters and when it doesn't.

What the cold does

A tomato's flavour is a mix of sweetness, acidity and aroma, and the aroma is carried by a range of volatile compounds. A team of researchers studied what happens to these when tomatoes are chilled. Their paper, Chilling-Induced Changes in Aroma Volatile Profiles in Tomato (Farneti and colleagues, Food and Bioprocess Technology, 2015), compared fruit kept at refrigerator temperature with fruit kept warmer and found that most aroma volatiles dropped during cold storage. When the tomatoes were brought back to warmer temperatures, levels rose again but generally did not return to those of fruit that had never been chilled, and recovery was weaker after longer spells in the cold.

In plain kitchen terms: a tomato that has spent a few days in the fridge tends to taste flatter, and letting it warm up helps only partly. Many people also notice the texture going woolly or mealy after a long chill, especially in ripe fruit.

So where do we keep them?

• Whole and ripe: at room temperature, stem side up, in a single layer, out of direct sun. Eat them within a few days, while they still smell of tomato at the stem.
• Not quite ripe: at room temperature too, where they can carry on colouring and softening. Never in the fridge, which slows that down.
• On the vine: leave them attached until you use them; it is simply easier to keep track of them that way.

For buying tomatoes worth keeping in the first place, see how to pick ripe tomatoes.

When the fridge is the right call

There are good reasons to chill tomatoes, and food waste is one of them.

• Cut tomatoes. Once sliced, keep them covered in the fridge and use them soon.
• Very ripe fruit you cannot eat in time. If they are on the edge of collapse, the fridge buys you a day or two. They will taste better cooked at that point anyway: sauce, soup, a tray of slow-roasted tomatoes.
• A heatwave kitchen. If your kitchen is properly hot, ripe tomatoes can go over fast. A short stay in the fridge is a reasonable compromise.
• Cooked dishes. Sauces, soups and anything with tomatoes cooked into it go in the fridge, covered, like any other leftover.

Rescuing a cold tomato

If tomatoes have been in the fridge, take them out well before you want to eat them so they come back to room temperature. Then help them along:

• Salt sliced tomatoes and leave them for a few minutes. The salt draws out juice and sharpens what flavour there is.
• Dress them with good olive oil, a few drops of vinegar and torn basil.
• Or cook them. Roasting or a quick sauce makes most of the difference disappear.

A cold tomato straight from the fridge is the version most likely to disappoint in a caprese, a salad or a raw sauce. Those dishes depend on aroma, so they are where room temperature matters most (more on caprese here).

What about tins?

Tinned tomatoes and passata live happily in the cupboard until opened. Once opened, transfer the leftovers to a covered container in the fridge and use them within a few days.