How long does food actually last in a freezer?

Why freezer times are quality limits rather than safety ones, realistic periods by food type, and what freezer burn actually is.

Difficulty: beginner
Time: 20 min
Read: 4 min
Safety: warning

Short answer

At -18°C food stays safe indefinitely. What degrades is texture and flavour, and that is driven by fat content and air exposure. Roughly: fatty fish three months, mince and cooked dishes three to four, lean meat six to twelve, bread three.

Freezer dates confuse people because they look like safety dates and are not. Nothing becomes dangerous in a working freezer — it becomes unpleasant.

Safety

Food stored at -18°C stays safe indefinitely — the times below are about quality, not safety. The exception is food that was not fresh when frozen, or food that has thawed and been refrozen, both of which carry real risk. If a freezer has failed and food has warmed above 8°C or been thawed for more than a couple of hours, do not refreeze it. When in doubt, throw it out.

Step by step

Understand the distinction.At -18°C bacteria cannot multiply, so food remains safe indefinitely. Every published freezer time is about eating quality, which is why they vary so much between sources.
Check your freezer actually runs at -18°C.A cheap freezer thermometer settles it. A freezer running warmer degrades food considerably faster, and many domestic freezers are not where their dial says.
Learn the rough periods.Fatty fish and sausages around 3 months. Mince, bacon and cooked dishes 3 to 4. Chicken pieces and pork 6. Whole poultry and beef joints up to 12. Bread and pastry around 3.
Know why fat is the limiting factor.Fat oxidises even when frozen and turns rancid, which is why oily fish and sausages have short times while lean beef lasts a year.
Remember vegetables and fruit.Blanched vegetables around 12 months, fruit 6 to 12. Unblanched vegetables deteriorate much faster because their enzymes keep working.
Handle dairy realistically.Milk freezes for around a month but separates — shake it and use it for cooking. Hard cheese freezes and crumbles, so grate it first. Cream and soft cheese generally do not freeze well.
Recognise freezer burn.Greyish-white dry patches where moisture has sublimed away. It is not dangerous and it is not mould. Cut it off — the rest is fine, though the texture will suffer.
Exclude air, which is the main enemy.Freezer burn is caused by air contact. Wrap tightly, press air out of bags, double-wrap anything staying long, and vacuum seal if you have the means.
Freeze in portions you will actually use.Nothing should be thawed and refrozen. Portioning at the point of freezing is what prevents that entirely.
Freeze it fresh, not at the end of its life.Freezing pauses quality, it does not restore it. Something frozen on its use-by date is what you get back when thawed.
Label everything with contents and date.The single most useful freezer habit. Unlabelled containers are why freezers fill with things nobody will eat.
Freeze flat and fast.Thin flat packages freeze faster, which makes smaller ice crystals and better texture. They also stack and thaw much more quickly.
Do not overfill or repeatedly open it.Temperature fluctuation is what causes large ice crystals and freezer burn. A full freezer holds temperature better than an empty one, but not if it is opened constantly.
Know the rules on refreezing.Raw thawed food should not be refrozen raw. Cooking it first and then freezing the cooked dish is safe and is the practical way round it.
Act properly after a power cut.A full freezer holds for around 24 hours unopened. If food still has ice crystals and is below 8°C it can generally be refrozen; if fully thawed and warm, discard it.

Tips

The times are about quality, not safety. Food at -18°C does not become dangerous.
Air causes freezer burn. Wrap tightly and press the air out.
Label everything. Unlabelled parcels are why freezers fill up with waste.

Common mistakes

Freezing food that is already near its use-by date — Freezing preserves the current state rather than improving it. Something frozen on the last day comes out as a barely-fresh product with degraded texture.
Refreezing raw food that has thawed — Each thaw allows bacteria to multiply and damages the cell structure. Cook it first and freeze the cooked dish instead — that is safe.

If it doesn't work

Grey dry patches on frozen meat

Cause: Freezer burn from air contact — Fix: Not unsafe. Cut the affected part away and wrap more tightly in future.

Heavy ice inside packaging

Cause: Temperature fluctuation — Fix: Check the freezer holds -18°C, stop overfilling, and avoid leaving the door open.

Food tastes stale or rancid

Cause: Fat oxidation over time — Fix: Nothing to be done. Keep fatty foods to around three months.

Watery and mushy after thawing

Cause: Frozen slowly, so large ice crystals formed — Fix: Freeze in thin flat packages so it freezes fast, and thaw in the fridge rather than at room temperature.

Freezer failed while you were away

Cause: Power cut or fault — Fix: If food still has ice crystals and is below 8°C it can usually be refrozen. Fully thawed and warm food should be discarded.

Questions people ask

Does food go off in the freezer?

Not in the safety sense. At -18°C bacteria cannot multiply, so food stays safe indefinitely. What deteriorates is texture and flavour, which is what the published times refer to.

Is freezer burn dangerous?

No. It is moisture that has sublimed away, leaving dry patches. The food is safe — just cut off the affected areas, since they will be dry and tasteless.

Why do fatty foods have shorter freezer times?

Fat oxidises even at freezer temperatures and eventually turns rancid. That is why oily fish and sausages last around three months while a lean beef joint lasts a year.

Can I refreeze food that has thawed?

Not raw food thawed raw. But you can cook thawed raw food and freeze the cooked dish — that is safe and is the usual way round the problem.