Freezing is a natural way of preserving food – we provide you with top tips to get the most from your frozen foods through safe storage and defrosting.
How does freezing preserve foods?
- It’s impossible for bacteria to multiply on frozen food – which makes it safer than any other form of food preservation.
- Foods today are ‘flash frozen’. This process, which freezes water in the food into smaller ice crystals, minimizing cell structure damage. Quick-freezing foods and then storing them at temperatures -18°C or lower slows the natural degradation process practically to zero.
- So, make sure you store your frozen food correctly, and it will retain its colour, texture, nutritional value and taste.
How can I store frozen foods safely?
Freezing naturally locks in nutrients and vitamins with no need for preservatives.
Follow the guidelines below to ensure that your frozen foods last longer and stay even fresher:
- All foods can be safely frozen, but some foods should not be frozen for quality reasons (lettuce, tomatoes, cucumber, cream etc.)
- Frozen food stored consistently at -18°C or lower will remain safe indefinitely
- Most domestic freezers should operate at temperatures -18°C or lower. As a general rule, if your freezer can’t keep ice cream solid, its temperature is above the recommended level
- Always refer to the on-pack ‘best before’ date. The manufacturer’s ‘best before’ date on frozen foods is a quality indicator and is the date until which the product will remain of peak quality (when stored at -18°C or below). For storage in a 3-star or 4-star freezer manufacturers will normally recommend ‘store until best before date’
- After the ‘best before’ date a reduction in eating quality may become evident, whilst the product remains safe to eat
- Try to rotate foods; putting newly purchased items at the back of the freezer so older items are used first
- Freeze your frozen food in appropriate containers, e.g. freezer bags and airtight containers.
- Most foods obey the rule ‘the colder the better’. Domestic freezers have a star rating indicating the temperature they are designed to operate at
- The freezer star ratings are as follows1
|Fast Freeze Temp in a **** Freezer = -26°C|
How long does frozen food last?
On the packaging of a frozen food item there is often guidance stating how long the food can be stored using freezers of a given star rating. As a guide here are some suggested MAXIMUM storage times at -18°C for a variety of foods.2
|Product||Practical Storage Life (in months)|
|Frozen Green Beans||18|
|Frozen Brussels sprouts||15|
|Frozen Corn on the cob||12|
|Frozen Potato Chips||24|
|Raw meat and meat Products|
|Frozen Beef joints, Steaks||12|
|Frozen Beef mince||10|
|Frozen Lamb joints, chops||10|
|Frozen Pork joints, chops||6|
|Fish and Shellfish|
|Frozen oily fish (herring, salmon, mackerel, etc)||4|
|Frozen fish, cod, haddock, etc||8|
|Frozen flat fish, sole, plaice, etc||10|
|Frozen Prawns, lobster, crab||6|
|Frozen Clams, oysters||4|
These figures refer to commercially frozen products; food frozen at home is unlikely to remain of high quality for the same length of time.
Your home freezer does not freeze foods quickly enough to minimise cell damage in foods because it does not get foods to freezing temperature quickly enough. Frozen foods and frozen meals from the supermarkets have been professionally and quickly flash frozen and so they retain their vitamins and nutrients, texture and colours as a result – the goodness is ‘locked in’.
Your home freezer is not designed to freeze foods from your kitchen but to store frozen foods from the shops.
Vegetables are frozen within hours of harvest
The ingredients in frozen meals and frozen food products can be fresher than ‘fresh’ foods because they are frozen at harvest and also because they are frozen at their peak of quality.
Flash Freezing seals in the goodness. Frozen vegetables have been proven to often contain more Vitamin C than fresh.
See below for info on how much Vitamin C is lost when ‘fresh’ vegetables sit around on shop shelves and in your fridge. ‘Fresh’ spinach loses 77% of its Vitamin C after just two days! And, bear in mind that fresh vegetables are often a week old by the time they reach our shops.
|Quantity of Vitamin C||(mg/100g)*|
|Freshly picked peas||22.1|
|Fresh peas (after 2 days)||14.1|
|Freshly picked spinach||17.0|
|Fresh spinach (after 2 days)||4.1|
|Freshly picked french beans||16.4|
|Fresh french beans (after 2 days)||7.9|
|Frozen french beans||14.3|
*Source: Deutsches Tiefkuhlinstitut
Frozen Pre-Packaged Meals
Frozen meals have surprisingly been around for much longer than you might imagine. The Romans and Ancient Chinese had been freezing their frozen foods in caves filled with snow for thousands of years before Clarence Birdseye made it accessible to all! Here are some of the benefits of frozen meals:
- The quality and taste of your food is preserved, because quick freezing prevents undesirable large ice crystals from forming in the items. Ready meals are frozen to lock in the nutrients naturally.
- Your food is less likely to become ‘freezer burned’, which happens when air reaches the surface of the food. This is because the methods of packaging used are completely air tight in ready meals.
- Because pre-packaged frozen foods and ready meals are frozen at peak quality, they come to your table tasting better than foods frozen near the end of their useful life.
- Vitamin content in frozen foods and frozen ready meals also often higher as freezing slows down the loss of vitamins and nutrients that occurs over time.
- Domestic freezers are designed to store frozen food, rather than freeze fresh produce. So frozen ready meals take advantage of the latest technologies in freezing the freshness in!
Keep frozen food fresh
Three ways of keeping that ‘just frozen’ freshness
- When you’re buying frozen food, always check that the packaging is undamaged.
- Always buy frozen foods at the end of your shopping trip before check out and pack your frozen items together.
- Put frozen items in freezer as soon as possible.
Cooking from frozen
- Many ready prepared foods can be safely cooked directly from the frozen state because the manufactures have designed the cooking method to ensure that the food is properly cooked. Therefore, if the pack tells you to ‘cook from frozen’ it is important to do so, as this will give the best results. Always follow the cooking instructions on the packaging carefully.
- Always cook vegetables from frozen in order to keep the nutrients ‘locked in’.
Refreezing thawed foods
- Refreezing thawed foods is not advised from a safety or quality point of view
- The main reason is to avoid the risk of improper defrosting methods, i.e. thawing at room temperature for too long a time or letting the thawed food get too warm before refreezing is started.5
Storing thawed foods
- Thawed foods should be treated as carefully as chilled foods, i.e. kept in the refrigerator
- Thawed frozen foods should be cooked as soon as possible
- Care should be taken to ensure that juices released after thawing do not drip onto the refrigerator surfaces – therefore, thawed meets should be stored covered at the bottom of a fridge for no more than 24 hours. Unless advised otherwise by the manufacturer.6