How to Freeze Food: Complete Guide — What, How and How Long

Freezing is the single most effective way to rescue food that would otherwise end up in the bin. According to WRAP, UK households throw away around 6.4 million tonnes of food every year — a substantial share of it perfectly freezable. Fango reminds you when fridge items are approaching their expiry date, but knowing what to freeze — and how to do it properly — is what turns that reminder into action.

Food frozen correctly stays safe and high quality for months, sometimes over a year. Food frozen incorrectly loses texture and flavour, or in worst cases creates a health risk. This guide covers everything: what can and cannot be frozen, the right technique, and precise storage times.

Freezer temperature — why it matters

Your freezer must be set to at least −18°C (0°F). According to the UK Food Standards Agency, at this temperature bacterial growth is effectively halted — bacteria don't die, they become dormant. The colder your freezer, the better quality is preserved over time: −20°C or −22°C is ideal for long-term storage.

Do not overfill the freezer. Air needs to circulate evenly so every area stays consistently cold. An overloaded freezer creates warm pockets near the edges where food quality degrades faster.

What can you freeze?

The majority of everyday foods freeze well when handled correctly. Here are the most common household items:

What should you not freeze?

Some foods don't survive freezing. Their texture, structure or safety is compromised to the point where the result is unpleasant — or in some cases risky:

• Whole eggs in shell — the shell cracks from pressure as liquid expands
• Salad leaves and fresh spinach — turn into a watery, limp mass
• Cucumber, celery and other high-water vegetables — structure completely breaks down
• Mayonnaise and mustard — separate and become grainy
• Soured cream and yoghurt — texture breaks down and becomes watery
• Soft cheeses (ricotta, cottage cheese) — become watery and granular
• Raw potatoes — turn grey and floury (cooked potatoes are fine)
• Carbonated drinks — expand and can split or burst the container
• Cream-based sauces — can split and separate when reheated

How to freeze food properly — 7 steps

1. 1
   Cool it first. Never put hot food straight into the freezer. Let it cool at room temperature for about an hour, then refrigerate until completely cold. Hot food raises the freezer temperature and risks partially thawing neighbouring items.
2. 2
   Freeze fresh. The fresher the food when frozen, the better the quality after thawing. Freeze meat on the day of purchase or the next day at the latest — don't wait until it's close to its use-by date.
3. 3
   Use airtight packaging. Air is the enemy of frozen food — it causes freezer burn (grey, dried-out patches). Use freezer bags (squeeze out all air before sealing), airtight containers, or vacuum bags.
4. 4
   Freeze in portions. Divide food into single or double servings before freezing. This way you only defrost what you need, rather than thawing a whole batch and risking waste.
5. 5
   Always label. Write the contents and the freezing date on every package. Three months from now you won't be able to tell mince from braising steak, or remember when it went in.
6. 6
   Freeze berries individually first. Spread berries in a single layer on a tray or baking sheet and freeze for a few hours. Transfer to a bag once solid. This prevents them clumping together, so you can pour out exactly the amount you need.
7. 7
   Blanch vegetables before freezing. Boil vegetables for 1–3 minutes, plunge into cold water, dry well, then freeze. Blanching deactivates the enzymes that otherwise degrade colour, texture and flavour during frozen storage.

How long does frozen food last?

Freezing doesn't stop quality from declining — it dramatically slows it. The times below are based on UK Food Standards Agency guidance, assuming airtight packaging and a freezer at −18°C or below:

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How to defrost food safely

Defrosting is as important as freezing itself. The wrong method significantly increases the risk of bacterial growth.

Safest method: fridge overnight

Transfer the frozen item from the freezer to the fridge the evening before. Meat and fish take 6–24 hours depending on size. This is the safest method because the food stays at or below 5°C throughout — the temperature at which bacterial growth is slow.

Faster method: cold water bath

Place the frozen food in a sealed bag and submerge it in cold water. Change the water every 30 minutes. A smaller portion defosts in about an hour. Cook immediately after defrosting this way.

Microwave defrost

The microwave defrost setting works well if you're cooking the food straight away. Don't leave microwave-defrosted meat sitting — it's already partially warmed and enters the bacterial growth zone.

What not to do

• Never defrost meat or fish on the kitchen counter at room temperature — bacteria multiply rapidly above 5°C
• Never refreeze raw meat or fish after thawing — cook it first
• Never defrost in hot water — the outside warms while the inside stays frozen

Freezing and food waste — the combination that works

UNEP estimates that around one third of all food produced globally is lost or wasted every year — a problem worth around £14 billion annually in UK households alone, according to WRAP. The most effective home strategy combines two things: actively tracking what's about to expire, and freezing it before it goes off.

Fango handles the first part automatically — scan your receipt and you get a push notification before anything in your fridge expires. When the reminder arrives, you know immediately: use it now, or freeze it. That single decision, made on time, is what stops food ending up in the bin.