Here's why your freezer smells so bad – and what you can do about it

Most people would expect a freezer can keep perishable food fresh and safe from spoilage for many months. Unfortunately, this is not always the case. Have you ever noticed a funky smell in your freezer? Where does it come from and what can be done to fix the problem?

Hardy microbes and pungent chemicals

• Although a freezer dramatically slows down the growth of most common spoilage microbes, some can still thrive if the temperature rises above -18℃ (the recommended freezer temperature).
• First, as microbes start to grow, several pungent chemicals are produced.
• When fermenting a food, we intentionally contaminate it with microbes of known characteristics, or provide conditions that favour the growth of desirable microbes and subsequent production of aromatic compounds.
• By contrast, uncontrolled food spoilage is problematic, especially when the contaminating microbes can cause disease.

Freezing changes the food

• Freezing causes physical changes to foods, often enhancing their breakdown.
• Many of us would be familiar with “freezer burn” on meats and other foods, as well as ice crystals on frozen food.
• In a similar way, as water in food freezes, organic molecules are concentrated and expelled.
• We call them “hydrophilic” or water loving; those are the ones that will make your food taste bad.

Help, my freezer smells!

• There are some simple steps you can take to stop your freezer from smelling.
• First, try to prevent odours from developing in the first place by covering the food.
• Placing some baking soda inside the freezer before adding food can help to absorb any residual odours.
• Make sure to clean your freezer now and then to keep your food safe and healthy.