Summer means strawberries are in season – and people will be flocking to the shops or waiting for them to grow in their gardens.

However, many might already know that you'll have to be quick after getting your hands on the berry, as they can often go bad just days later.

To help, Great British Bake Off star Nancy Birtwhistle has shared her go-to tip on food storage. Apparently, you can add just one ingredient to your strawberries that will help them last for up to two weeks when stored in the fridge.

She told her Instagram followers: "I'm just in from the supermarket. I've bought myself some strawberries in here and when you look on the pack, it does say wash before use. So I'll show you how I wash mine to not only get rid of any pesticides and bacteria and what have you, but also expand their shelf life...

"Oh, and these strawberries will offer me an extra little free gift, let me show you."

To wash her strawberries, she added two teaspoons of citric acid into a large bowl along with 60ml of boiling water. Stir and let the citric acid desolve before adding in 400ml of cold water.

Then, add the strawberries into the bowl of water and wash them before moving them to dry.

"No need to rinse them, just drain them, store them in a jar," she said. "These strawberries will last up to two weeks in the fridge."

She then went on to urge people not to tip away the water that the strawberries had been washed in, but instead pour it into your kettle.

"You don't want to throw that water away. Use it to descale the kettle - gorgeous," she said as she showed her now clean kettle. "And then use it to clean the sink afterwards."

When the time comes for you to prepare and cut up the strawberries, Nancy urges you to save the tops of the berries that usually get cut off.

She demonstrated: "I'm just slicing the tops off rather than pulling them. And I'm saving those strawberry tops. When I've got 100 grams, I put them into a large jar and add exactly the same weight in sugar."

Nancy then went on to shake her jar of strawberry tops and sugar before putting it back into the fridge. Go back to shake it every day for five days in a row.

"And after five days, you've got the most amazing, clear, strawberry syrup," she revealed as she showed off the syrup she'd just made.

Simply strain it through a coffee filter and into another jar, then you're good to go. Nancy says the syrup works great alongside ice cream or any other dessert.