Do you keep your ketchup in the cupboard? Or maybe your onions and potatoes are huddled up together in your pantry? If so, you might want to rethink where you store your food to make it last longer. From produce that should always be kept in your fridge to foods that you should never freeze, these are the storage rules you need to know.

Cold temperatures turn starch in potatoes into sugar, which can make them discoloured and bland. Potatoes should be stored unwashed and in a well-ventilated spot well away from any sunlight. If possible, keep them in a burlap sack or a wicker basket.

Aubergines don't need to be kept in the fridge, but be careful not to leave them somewhere too warm, or they'll shrivel up. It's important to find a happy medium if you want to get the best from this ingredient: house them in a cool, dark place away from direct sunlight.

So long as you’ve not contaminated the jar with a dirty spoon, the preservatives used in manufactured pickles mean they should last just fine in the cupboard, freeing up precious fridge space. Make sure the lid is tight and check the use-by date (and any specific instructions on the label). However, if you're storing fermented pickles or you've pickled your own veg, these are best kept in the fridge.

Labels on bottles of soy sauce may state it should be refrigerated, but restaurants safely leave the condiment on tables all day. The truth? The high salt content means it can be stored at room temperature for up to six months.

If you’re not planning on opening a bottle of Champagne or sparkling wine within five days of putting it in the fridge, don’t keep it stored there as the fluctuating temperature of the door opening and closing will wreak havoc on it. Champagne is best stored on its side, away from light, in a room with a consistent temperature. Chill a couple of hours before you want to open it.

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Fridge temperatures damage tomatoes' membranes, causing them to become watery and mealy. Storing them in the fridge will also permanently dampen their flavour. The best place to put tomatoes is out on a counter or worktop.

Soft herbs like basil, coriander, mint, parsley and dill should be treated like bunches of flowers – trim the stems and keep them in a glass with fresh water. If confined to the fridge, the leaves will wilt and quickly become soggy. However, hard herbs such as rosemary, thyme, sage and oregano should be wrapped in a paper towel and stored in an airtight container in the fridge crisper drawer.

Butter is virtually unspreadable straight from the fridge and it’s perfectly safe to store a block (or stick) in a covered dish on a worktop for a day or two, says the USDA's FoodKeeper App. However, you don’t want it to melt or go rancid so transfer it somewhere cooler, out of direct sunlight in the hot summer months. If you don’t plan to use the butter within a few days, it’s best kept in the fridge.

Don’t be tempted to slip fresh peaches in the fridge if they’re not yet ripe and ready. Like many other stone fruits, cold temperatures hinder the ripening process, meaning you’ll be left waiting longer to dig in. They’re also at a higher risk of spoiling. Store them on the countertop instead and only chill to make them last a bit longer if they’re about ready to tuck into.

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Warm temperatures, around 15–20°C (59–68°F), are needed for a banana to ripen correctly, and this process is halted when the fruit is put in the fridge. The skin may also eventually turn black in the fridge because of the impact the temperature has on a banana's cell walls.

With similar shelf life and storage requirements, you might be tempted to store potatoes and onions together, but it's a bad idea. Onions produce a small amount of ethylene, which has a very significant effect on potatoes. Spuds will start to sprout and can even grow a decay-causing fungus. Separate the two vegetables and they'll last up to a month in your pantry. It's worth noting that it's fine to store garlic with onions though.

Pumpkins and other types of squash might be hardy on the outside, but they're very susceptible to ethylene produced by fruit. Keep them apart and your pumpkins (as well as both summer and winter squashes) will keep for significantly longer – pumpkins can last as long as three months in the pantry, if stored on their own.

Cucumbers are especially sensitive to ethylene, so unless you want to see accelerated decay and yellowing, keep them as far away as possible from any other fruit or veg. They also won't last very long in the fridge – only up to six days – so make sure you only buy what you need and use it up quickly.

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More veg that will start to yellow prematurely in the presence of ethylene, broccoli and cauliflower are also highly sensitive to the gas. The leaves will start to detach from the stalks and go limp if they're kept close to apples, melons and tomatoes. These brassicas also have a relatively short shelf life so keep them in the fridge away from other produce and they'll keep for up to five days.

Carrots are also sensitive to ethylene. The popular root vegetable is quite hardy and will last up to three weeks if refrigerated, but if you keep them close to ethylene-producing foods like apples, potatoes or tomatoes, they'll start to develop a bitter taste rather quickly.

You might be surprised to find out that dates are best stored in the fridge, despite the fact other dried fruit is fine the cupboard. This is because dates are not as dehydrated as other dried fruit, like cranberries or apricots. As they still hold a bit of moisture, it's best to keep them cool in an airtight container to preserve their flavour. If you store them outside the fridge, they will progressively become drier and lose their flavour. 

One of the few fruits that benefit from refrigeration are apples. This is because apples release ethylene gas, which speeds up the ripening of any nearby fruit and veg. If kept in the fridge, the production of ethylene is slowed down, making them (and other fruit) last longer. Just make sure you don't keep the apples together with other vegetables, and cover them with a damp paper towel or store in a plastic bag with holes.

Despite its high sugar content, pure syrup can and will spoil, if not refrigerated. There are no preservatives in pure maple syrup so over time it will develop a layer of mould on the surface, if kept at room temperature. For long-term storage, you're better off keeping it in the fridge. 

Whether ketchup should be stored in the fridge or in the store cupboard is somewhat of a contentious question. While it would be safe to assume that due to the ketchup's high vinegar, salt and sugar content it's safe to store at room temperature, it isn't exactly the case. Heinz has confirmed that thanks to its natural acidity, Heinz Ketchup is shelf-stable. However, as soon as you've opened your bottle, the storage conditions can affect that stability. "We recommend that this product, like any processed food, be refrigerated after opening," says Heinz.

In the US, eggs are sterilised after production to kill bacteria, which also weakens the eggshell. This means they should be kept cool to prevent the bacteria from returning. In most of Europe, disinfecting eggs is illegal and the EU recommends that eggs are kept cool but not refrigerated.

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One way to preserve produce – especially watery vegetables such as tomatoes, courgettes and green beans that can go soggy – is to turn them into a healthy sauce which can be frozen, then defrosted and cooked when required. Ratatouille and vegetable-packed tomato sauce are two great options.

Made too much batter? Don’t discard it – it can be kept in an airtight container in the freezer for up to a month. Alternatively, freeze in a zip-lock bag so it can lay flat and save space in the freezer. Defrost thoroughly before using.

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Similarly, any excess dough and raw pastry can be frozen if wrapped tightly in cling film. It’s best to do this soon after preparation so it doesn’t dry out. This also applies to fresh yeast, and dough that contains yeast and has risen. Thaw overnight in the fridge.

Scrambled eggs are one of the best ways to freeze eggs because the mixed-in yolk prevents the whites from becoming too rubbery. First cook so the eggs are slightly under, then allow to cool and freeze portions in a cupcake tin for no longer than half an hour. Remove and put into individual freezer bags, squeezing out any air before closing. Allow to defrost in the fridge overnight before reheating in the microwave or a frying pan.

Cooked pancakes can also be frozen for a couple of months. To store, allow the pancakes to cool down then put greaseproof paper between each one before wrapping tightly in cling film. You can reheat from frozen in a microwave, the oven or in a toaster – just keep an eye on them so they don't go too crispy or burn.

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Eggs frozen in their shell will explode because liquid expands as it becomes solid. However, you can freeze raw egg white. Just add a sprinkle of salt or sugar to prevent the eggs from turning rubbery and ensure there’s enough space in the container for the eggs to expand slightly when frozen.

Icing made with egg whites can separate if frozen and then defrosted. This can and will ruin a cake, so instead freeze the cake and make the icing fresh.

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Storing cooked rice in the fridge or freezer is the cause of much debate, but you have to be aware of the risks. Cooked rice left at room temperature is a breeding ground for bacillus cereus, a bacterium that causes food poisoning. If you do want to keep rice, make sure it cools quickly and keep in the fridge no longer than a day. When reheating it, make sure it’s heated through thoroughly and is piping hot.

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Potatoes have a high water content so if they're frozen, that water freezes, causing ice crystals to form which affects the taste and texture once thawed. One way around the problem is to part-cook or completely cook the potatoes before freezing, but it’s generally better to avoid.

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Cucumber, lettuce, radishes and salad greens have a high water content, which causes this produce to turn limp and mushy when defrosted. Buy and eat fresh is the only rule you should remember when it comes to salads.

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