What is freezer burn?

Freezer burn is essentially dehydrated (dried out) food. The 'burn' is a bit of a misnomer because the processes that lead to freezer burn occur within the harsh, sub-zero environment of your freezer.

Over time, some of the vibrating water molecules in the ice within your frozen food will break free to form water vapour (this is known as sublimation). This vapour will eventually escape from the food, causing it to dry out.

Of course, not every item in your fridge will end up being damaged by this process, so what is freezer burn actually caused by?

The two main reasons freezer burn happens

In most cases of freezer burn, inadequate packaging is the main contributing factor. When packaging items for frozen storage, your goal is to minimise air exposure. Vacuum packing is the ideal solution because that removes most (but not all) of the air molecules from the packaging.

Returning to the method of sublimation explained in the above section - 'What is freezer burn?' - water vapour is more likely to escape food if it is surrounded by air, particularly the dry air of a freezer. a sure sign that this has occurred is a coating of ice crystals on the surface of the food. This is due to the deposition of water vapour back into ice. Exposure to air also leads to oxidation which can also affect the flavour, texture and colour of the affected food.

The other main culprit of freezer burn is storing your frozen produce for too long. As mentioned above, sublimation is a naturally occurring phenomenon which will eventually dry out any frozen food item. Even the best vacuum packing equipment is never going to remove every molecule of air. This is why frozen food has a maximum storage period.

Is food with freezer burn safe to eat?

What is freezer burn in relation to health and safety? If you've been eating or selling freezer-burned food, the good news is that freezer burn has nothing to do with the pathogens that cause food to spoil. So providing you have robust food hygiene processes in place, there is nothing to fear on safety grounds.

The health of your business is another matter because if you are selling or serving food with freezer burn, the customer will not be impressed. Not only will the affected food look dry, misshapen and discoloured, often with white or dark patches, it will also taste bland. Meat and fish will feel tough to chew while fruit and veg will become mushy when defrosted.

The best defence against freezer-burn is to package your frozen food well and maintain an efficient freezer workflow. Here are some tips:

• Rotate frozen food systematically to avoid forgetting items
• Minimise the number of times you open the freezer door
• Minimise the time you leave the door open for
• Cool hot items in a fridge or ice bucket before freezing them

Could your door seals be making freezer burn worse?

Yes! A stable freezer temperature can help prevent or mitigate the effects of freezer burn by keeping water movement and other processes to a minimum. Anything which causes the temperature of your fridge to go up and down will accelerate the processes behind freezer burn.

This can include inefficient freezer usage (e.g., constantly opening and closing the door) and a dirty or damaged door seal. We have written plenty of articles on how to clean and check your door gaskets, and we can quickly replace the seals on almost any freezer.

If a worn or broken gasket is making your freezer burn problem worse, use our resources to rapidly track down a replacement.