Freezers – where does all that ice come from ?
We have all seen that “snow” that forms in freezers and on frozen product. This is moisture coming from the food within the freezer. This is dehydration and can be seen as freezer burn on products.
A freezer works by moving cold dry air around the space, and when this air becomes full of moisture, snow / ice and freezer burn occur.
So what impacts on this dehydration;
- Incoming air temperature
- Freezing time
- The moisture content of the air
- The amount of water on the surface of the food
- Moisture content of the food
- Air speed
- The size of the food product in terms of surface and volume
Another factor is the container the food is in. Solid plastic containers will protect the food better than a thin plastic film or cardboard box although it only slows the process down.
Colder air will naturally be dryer, which increases it’s capacity to draw moisture from the food. So freezers are the ideal situation for this precipitation and subsequent dehydration to occur.
Freezer burn and snow / ice decreases the weight of the food and it’s appearance. So it is in the interest of each manufacturer to do what it can to reduce the impact of this process and provide the highest quality product possible.
The key to preventing snow / ice and freezer burn is to keep the air moisture content high enough to prevent the dehydration occurring. This is not something that food manufacturers can control, however they can adjust the product packaging to provide better a better moisture barrier. The problem with this is that such packaging is obviously more expensive, so is not always suitable for each type of product.
The consumer has a large part to play in reducing this process – by making sure that product is turned over regularly to reduce the amount of time that their food is in the cold dry air.