Onions are a kitchen staple, but there is always a little uncertainty about where exactly you’re meant to store them: the fridge or the cupboard?
Well, it depends. If your onions are still whole, specialists say keep them in a cool, dark and dry place to make sure they stay fresh and so they have a longer lifespan.
As the experts at KJ Refrigeration explained, onions are known for easily absorbing moisture (which is probably why they’re so great as a base for a sauce) so if you put them in humid conditions, they’re more likely to get ruined.
“You should make sure onions are in an area with good air circulation to avoid them becoming mouldy,” KJ Refrigeration explained.
The UK’s Food Standard Agency (FSA) agrees that onions of the brown, red and white are all best kept in the cupboard – although it advises refrigerating spring onions and leeks.
But, if they’re already sliced and diced, put them in the fridge in an airtight container and make sure you use them up in the next few days.
It’s also a good idea to put a paper towel in there to absorb excess moisture.
Once onions are cut, they’re more likely to become contaminated if you leave them out in the open – so putting them in the fridge means they’re less likely to go off.
KJ Refrigeration did also pass on an essential tip – do not, ever, store onions next to potatoes. They might be great companions once they’re in the pan but they really don’t get on well in the cupboard...
The refrigeration and air conditioning experts said: “This is because onions emit a gas called ethylene gas that fastens up the ripening process.
“This gas is also found in other foods like apples and tomatoes.
“Therefore, if onions and potatoes are stored next to each other, potatoes may sprout and prematurely spoil.”
They added that potatoes also had high moisture levels so onions can become “leaky and mushy” – so the two should definitely be stored far, far away from each other.
In fact, the FSA updated its guidance in 2022 to say that you should actually put your tatties in the fridge to make them last longer.
It even goes one step further on its website, and suggests: “You can freeze cooked or parboiled potatoes which have been boiled for 5 minutes.
“Leftover cooked potatoes can also be frozen. You can roast boiled potatoes straight from the freezer, make sure they are steaming hot all the way through. Put them in the oven with a little oil to crisp up. ”
And, data from the Waste & Resources Action Programme (WRAP) found refrigerated potatoes can last more than three times longer compared to when they’re kept in the cupboard.
So – onions in the cupboard, potatoes in the fridge. Sorted!