Whether it's preserving batch-cooked meals, safely storing leftovers or keeping convenience foods in peak condition, the domestic freezer is one of the handiest, hardest-working appliances we can own. But not every food is robust enough to withstand its sub-zero temperatures – plus, dehydration, rehydration and freezer burn can afflict many delicate dishes and ingredients. To help you figure out what should be kept where, we've complied a list of common foods that should never be consigned to the freezer.

Click or scroll through our gallery to discover 26 foods you should NEVER freeze, from avocados to yogurt.

Internet hacks will tell you that avocados can be frozen with careful preparation – chopping, dressing in lemon juice, and fast freezing. However, that buttery texture and vivid green colour will be lost, leaving you with a mush that's pretty useless (unless you can hide it in smoothie). Avocados also brown when they're exposed to oxygen as they defrost, as enzymes in the flesh alter the chemical structure of the phenols – compounds that can be found in abundance in these heart-healthy fruits.

If you know your beans, you'll know the delicious aromatics that emerge from coffee mostly come from flavour compounds within the beans' natural oils. Preserving the life of these oils is a good instinct, but the freezer can't help. All that frosty build-up in your ice box? That's atmospheric moisture – and ground beans can easily absorb it, ruining the stability of those essential oils. Any strong flavours will also be absorbed, giving your posh beans an aftertaste of the likes of garlic bread, fish fingers and diced onions.

Vegetables with a high water content will cope poorly with the freezing process, as their delicate liquid-containing cells (which, when fresh, give them such a satisfying crunch) will be blown apart as the liquid expands into ice crystals. This means that the onion and cabbage in coleslaw will become limp and mushy, while the mayonnaise (which we'll get to later) will suffer its own issues. In short, leftover coleslaw should never go into your freezer cabinet.

The high water content in cream cheese makes it prone to bacterial spoiling before you get around to using up the full tub. But be warned: store this high-fat cheese in the freezer, and that gorgeously silky consistency we all love will turn grainy, crumbly and wet. Yes, frozen cream cheese can still be used in cooking – stirred through a soup maybe, or baked into brownies – but it'll be no good on a cheese board or spread over a bagel.

Freezing cucumber batons may feel like the ultimate get-ahead canapé trick, but it's really not such a great idea. A high water content means the cells walls in this classic salad vegetable will expand and burst as they freeze. The solid sticks may make a cute garnish for a gin and tonic, but when defrosted, the batons will be a bendy mush. That glorious crunch will be gone, and your cucumber will be fit only for the compost bin.

Trifles, brûlées, and bakes filled or topped with custard are too good to waste, so we won't blame you for wanting to make your leftovers last. But while authentic egg-based custards are just divine enjoyed fresh, they undergo an unfortunate transformation as they defrost. The egg, cream and milk combo will lose its lovely silkiness and become watery and lumpy as the ice crystals melt. However, a pouring custard will fare better if first churned in an ice cream maker and stored for a short period of time.

Eggs are so perfectly packaged – and perishable – that it's tempting to pop an excess directly into the icebox. However, if you do so, the expansion of freezing liquids will once again be your enemy. The shells of whole eggs crack as they freeze, allowing bacteria in your freezer to contaminate the interior (and causing an almighty mess as you defrost). A practical solution is to break and separate the eggs you wish to preserve, transferring the whites into ice cube trays for freezing. Yolks can change texture as they thaw, so they're best beaten with a little sugar or salt before freezing.

Delicate rose petals or frothy elderflowers can make a beautiful addition to cakes and desserts. Some cooks even mill them into pasta dough or glaze them onto sourdough loaves for a beautiful aesthetic. However, sadly, preserving their beauty in the freezer is doomed to fail; the petals will turn to a brown slush as the ice crystals defrost. If you're desperate to press pause on edible blooms, try setting them into ice cubes – but for decorative garnishes, use fresh or dried flowers.

There's a really good reason those pre-frozen fried foods we buy at the supermarket contain such a long list of industrial-sounding ingredients. Maintaining the dry and crispy structure of fried foods is a real science. Fresh or homemade fried foods will succumb to one of the biggest problems associated with the freezing process: moisture. The delicate bubbly structure of a batter – or the crispy coating of a fried ingredient – will buckle as it defrosts.

Aromatic Thai basil, fragrant coriander and tender tarragon can make or break a dish, but don't be tempted to store any leftovers in the freezer for next time. These soft herbs – a category that also includes mint, parsley, dill and chives – will turn black and slimy when thawed, so they'll always need to be processed into a paste with a protective glug of oil before freezing. Tougher herbs such as rosemary, bay leaves and lime leaves will fare better frozen just as they are.

If a picture-perfect aesthetic is your aim, don't attempt to freeze icing made with raw egg whites ahead of use. While a sponge cake will freeze and defrost perfectly, any egg white in the icing can thicken and separate from its fellow ingredients as it thaws, causing unpredictable flaking – and thereby spoiling your flawless finish. Some pros use dehydrated egg whites in powder form; another alternative is to bake ahead, but ice fresh every time.

Whether you love whole fruit jellies, the wobbly layer of a trifle or even the meaty gel in a pork pie, we have bad news. Those magical springy chemical bonds in gelatine that give jelly its bounce and wobble sadly don't survive the freezing process. Some vegan alternatives can be freezer-stable, but the thawing process is hit and miss; if carrageenan or agar are the gelling agents in a packet dessert mix or mousse, tread carefully.

Mayo keeps well in the fridge, so why would you freeze it? Well, it can be tempting to freeze mayo-rich sandwich fillings and sauces – and if you've made a batch from scratch, you'll want to keep enjoying it forever. But hold on; this stable emulsion of oil, egg yolk and vinegar will completely lose its composure as it thaws from frozen. Expect a melty, clumpy mess that doesn't live up to its original texture.

Whipped egg whites and sugar make for truly magical clouds of meringue when served fresh – but pop them in the freezer, and it's a different story. The difficulty comes down to the effects of moisture; if you can eliminate water droplets while your French, Italian or Swiss meringue is stored in the freezer, so much the better. But as you defrost it, any condensation on its wrapping will cause the texture to soften, losing all that wonderful crack and crumble. Soft meringue toppings can also be rubbery after defrosting, so we recommend against storing them in the freezer, too.

With food prices skyrocketing, it's tempting to snap up those cheap, nearly expired products and pile them into the freezer to enjoy later. But here's the rub: freezing doesn't restore a food's freshness, and thawing is a fine art even for the freshest of foods. Freeze those that are already at the borderline when it comes to food safety, and you have a recipe for food poisoning. If you leave these items to defrost at room temperature, bacteria will have time to build – and if you warm them in a microwave, you risk accelerating spoilage. That modest cash saving just isn't worth the risk.

They're one of life's most decadent delicacies, yet there are few foodstuffs as high risk as raw oysters. These filter feeders can harbour and concentrate seriously harmful bacteria in their soft flesh, so they require careful handling at home. Freezing raw oysters is technically possible if you defrost them at a low temperature, but you should cook them soon after to sidestep the tricky textures caused by melting ice crystals. Take our advice and cook your oysters before freezing, or just enjoy them fresh and at their best.

As handy as long-term storage for this store-cupboard essential would be, the water content in potatoes makes them unsuitable for the freezer cabinet. To preserve the sweet springtime flavour of new potatoes, you can par-cook them before freezing; however, the results will be disappointing. It's better to carefully cut your spuds into smaller pieces (a whole potato will take an age to defrost) and pre-cook them in the oven or steamer before consigning them to the freezer.

These peppery salad vegetables add a pop of colour to summer plates – but if you have a glut from the garden or leftovers in the fridge, think twice before putting them in the freezer. The high water content of these crunchy vegetables makes them vulnerable during the freezing process, meaning they'll be soggy and sad after defrosting. A much better idea is pickling, which can preserve radishes' colour and flavour for weeks.

It's worth remembering that the freezer pauses, but doesn't eliminate bacterial activity within foods. This means that foods at high risk of containing pathogens, particularly raw meat, fish and shellfish, need extra-careful handling. When we cook these proteins before refreezing, the heat kills off most of the microbes present, lowering the risk of food poisoning. But when defrosted foods are refrozen without this step, harmful bacteria are given extra time to multiply, which can cause a nasty bout of food poisoning.

Bagged salad is one of the most common sources of food waste, those delicate fresh leaves wilting under plastic in our fridges. However, don't be tempted to press pause on the process with a stint in the freezer. The water-rich cells in each leaf will burst upon freezing, leaving you with an unappetising green mush as your only reward. But before you bin your half-eaten bag, check the varieties of leaf inside. Baby spinach, beet greens and watercress can be cooked, then frozen to store some nutrients.

Dairy products are essentially emulsions of fat and water particles, two constituents that react very differently to the freezing and thawing process. This may sound counter-intuitive since ice cream is a one of the tastiest freezer foods of all time, but plain old cream won't fare well in your freezer. It's all about the structure; a scoopable ice cream has to be churned or whipped to inhibit the growth of large ice crystals. The higher the fat content in a dairy product, the fewer ice crystals will grow – so if you really want to freeze cream, opt for double.

The freezer is a great place to store leftover pieces of crumbly ingredient cheeses – Cheddar, Parmesan and Stilton, for example – which can be slipped into a soup or bake for added flavour. What won't work, though, is preserving silky, runny cheeses with more complex textures, such as Brie or Camembert. That's because a higher water content within the paste of these cheeses means their structure will be severely impacted by subzero temperatures. You'll just have to work extra hard to enjoy those cheeses fresh!

There's nothing so glorious as a perfectly ripe, fresh tomato – but if you freeze one, what will emerge from your freezer will be nothing like its former self. From the gel-like pips to the complex structure of the flesh, the delicate texture of this fruit will be torn apart by expanding ice crystals as it freezes. There's no good reason to ruin tomatoes in this way, so be sure to cook and chop (or purée) batches destined for the freezer.

Having portions of this creamy dressing on hand is useful when you want to jazz up salads, wraps or grilled vegetables. But sadly, the freezer is not a safe place for this gorgeously garlicky dip. As we've seen, watery cucumbers turn to a slimy mush as they thaw – and their yogurt coating won't fare much better, as it will separate into curds and whey. If you love tzatziki, make it fresh, in small portions, and remember to keep it away from the freezer.

It's the ultimate summer cooler, so it makes sense that watermelon would be great frozen, right? Wrong! Those delicate cell structures that deliver lip-smacking juice when fresh will be damaged beyond repair by the low temperature of your freezer. Left to defrost, your watermelon will completely collapse, leaving you with a somewhat slimy red mush. A powerful blender may save the day, though, blitzing the iced hunks into a tasty slush; just make sure to use small chunks.

It's natural to want to preserve this cool, creamy ingredient for future use, but popping yogurt in the freezer simply isn't a good idea. When stored at subzero temperatures, the fats and water in yogurt will separate into large frost formations, creating a split texture – not to mention an extra-acidic taste when defrosted. To put your leftover yogurt to good use, make labneh by salting and straining away the excess whey.

Now discover 39 foods that should never be stored in the fridge