Freezing Food Near Its Use-By Date: What Is Safe?

Everyone knows the situation: you have done a big shop, the fridge is packed, everyday life is hectic – and suddenly the critical date on the packet is approaching. Chicken breast, mince or salmon fillets are then quickly put into the freezer. A virologist explains when this is still acceptable, where the real risks lie and why handling date labels correctly remains essential.

What really happens when food is frozen shortly before expiry

Océane Sorel, a virologist known in professional circles for her work on viruses and micro-organisms, takes a matter-of-fact view of spontaneous “last-minute freezing”: as a rule, a properly chilled product that has not changed can still be frozen on the day before its use-by date – and sometimes even on the date itself.

Freezing only stops bacteria temporarily. They do not die; they simply pause.

Sorel uses a memorable comparison: freezing works like the pause button on a remote control. Most germs stop multiplying, but they remain present. Once the food defrosts, the film resumes – and the bacteria continue from where they stopped.

That is the crucial point: anyone who freezes a product only after it has spent many days in the fridge also freezes the bacterial load that has built up over that time. When it is defrosted, this “microbial community” becomes active again and can continue spreading. This is not automatically serious for healthy people, but the likelihood of stomach and bowel problems increases.

Use-by dates and best-before dates: navigating food labels

Before reaching for the freezer, it is important to understand which date is actually shown on the label. Many foods are unnecessarily thrown away because the distinction is unclear.

Use-by date (DLC): this is the strict limit

The wording “Use by …” identifies particularly perishable foods. These include:

• Fresh meat products, including mince, steaks and poultry portions
• Fresh fish and seafood
• Fresh dairy products, such as some desserts or products made with raw milk
• Chilled ready meals with a short shelf life

Once this date has passed, the product is considered potentially risky. Experts draw a clear line here: if the use-by date has expired, the food should neither be eaten nor frozen. Even if it still smells fine, invisible germs may already have reached levels that can cause unpleasant consequences.

Best-before date (DDM): quality rather than safety

The wording “Best before …” belongs to a different category. It mainly applies to longer-lasting products such as:

• Pasta, rice and flour
• Tinned food and jarred products
• Chocolate, biscuits and crisps
• Dried pulses, coffee and tea

After this date, flavour, texture or colour may deteriorate slightly, but the food is often still perfectly edible. Many consumers discard these products because they are unsure. Studies show that vast quantities of edible food end up in the bin because of this confusion: a loss of quality is mistaken for a health risk.

Last chance for the freezer: when “late” can still be safe

Health authorities advise freezing meat and fish as soon as possible after shopping if it is clear that they will not be cooked promptly. Anyone who acts only at the last minute should look more carefully.

Freezer emergency checklist

Before putting a product into the freezer on the day before its use-by date, carry out a quick safety check:

• Visual check: There should be no discolouration, slimy coating or unusual surface deposit.
• Smell test: Does it smell neutral or as expected? Musty or sharp smells are a clear warning sign.
• Packaging: Is it still sealed, with no tears or swollen areas?
• Chilled storage: Was it refrigerated promptly after purchase, rather than left in a warm car for a long time?
• Fridge temperature: Ideally, this should remain consistently at around 4 °C or below.

Anyone freezing food late should check twice that the product still appears to be in perfect condition.

If there is any doubt, it is better not to put the food into the freezer and to throw it away instead – however financially painful that may be.

How long can frozen food be kept?

Once a product has safely gone into the freezer, time plays a different role. At -18 °C, bacteria remain dormant, although quality and flavour gradually change. Practical household guidelines are:

These times relate to quality, not to a strict safety cut-off. Writing the freezing date on the packet with a pen makes it easier to keep track and prevents packs from disappearing among ice crystals for years.

Defrosting correctly: where most mistakes happen

Defrosting is at least as important as the point at which food is frozen. This is when bacteria regain their advantage. Experts recommend:

• Defrosting food in the fridge, ideally on the bottom shelf in a bowl.
• Alternatively, using the microwave defrost setting immediately before cooking.
• Never defrosting at room temperature on the kitchen worktop.
• Not reusing defrosting liquid; pour it away instead.

Defrosted food should be cooked promptly and eaten soon afterwards. One rule is especially strict: food that has already been defrosted should not be returned to the freezer – particularly if it was already close to its use-by limit before it was frozen for the first time.

Reducing food waste without putting health at risk

The real everyday challenge is clear: nobody wants to throw away food unnecessarily, but nobody wants to experiment with spoiled mince either. A sensible approach to fridge storage can help achieve both aims.

It makes sense to plan roughly while shopping: what will be eaten today, what tomorrow and what is unlikely to be used? Products intended for later are best put straight into the freezer after unpacking. The last-minute rescue on the day before should then be the exception, not the routine.

Useful measures include:

• A clearly visible “eat soon” shelf at the front of the fridge.
• Freezing small portions rather than large blocks, so everything freezes through completely and defrosts more quickly later.
• Planning meals two or three days ahead instead of playing unplanned fridge Tetris.

Why children, pregnant people and older adults need to be especially careful

People with a robust immune system often cope with minor food-hygiene mistakes without serious consequences. For some groups, however, the situation is different: pregnant people, young children, older adults and people with chronic illnesses are considerably more sensitive to germs in food.

In these households, it is worth taking an especially strict approach to date labels and storage conditions. When in doubt, it is better to use the freezer sooner – or to decide against late freezing and shop more cautiously next time.

Anyone who understands the basic principles – reading dates correctly, freezing in good time and defrosting hygienically – gains greater flexibility in the kitchen. The freezer then becomes not a last-minute fallback, but a well-considered tool for reducing food waste without putting health at risk.