The ideal fridge temperature should be between three and five degrees – but the average temperature in UK fridges is seven degrees, which is verging on too warm for the ingredients inside.
Food stored in temperatures eight degrees or higher can start to rapidly grow harmful bacteria, meaning it will go off sooner than it should – creating food waste.
But when stored at five degrees or lower, fresh foods like fruit, vegetables, and milk can last for three days longer or more.
As a result, condiments makers Hellmann's have created a new “smart jar” of mayonnaise, which tells you if your fridge is too warm.
The label on the mayonnaise jar uses heat-sensitive ink, which reveals hidden messages and quirky graphics once temperatures drop below five degrees.
Any foods kept at higher temperatures are likely to deteriorate at a faster rate, according to a study by food waste charity, WRAP – and this includes shop-bought mayonnaise, once opened.
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The new prototype “smart jar” label, unveiled to mark Food Waste Action Week 2023 (March 6th-12th), was designed by illustrator Ellen Porteus.
Rachel Chambers, of Hellmann’s, said: “We know how important it is to make the most of the food you buy.
“We’re constantly looking to help consumers reduce food waste and save money, and we think “smart jar” is an innovative way to get people talking about – and solving – this massive problem.”
The condiment maker’s partner, WRAP, has also developed an online tool explaining how to set any brand of fridge to the optimum temperature – to reduce food waste.
Catherine David, director of collaboration and change at WRAP, said: “Every year more than 4.5 million tonnes of perfectly good food goes to waste in our homes, which could have been eaten.
“This costs the average family upwards of £700 a year – money none of us can afford to waste.
“Incorrect storage is a key trigger for food going off, and getting the fridge temperature right can help food stay fresher for longer.
“I'm delighted WRAP has worked with Hellmann’s on this exciting trial. We need innovations like this pilot jar to help us make simple changes in our lives that will pay dividends.”