How to Prevent Freezer Burn
1. What is Freezer Burn?
Freezer burn occurs in meat and other frozen items (especially meat), where the water sublimates (goes from a solid to a gas) and then condenses as ice crystals. This leaves the food severely dehydrated, with a stiff, stringy texture that most people consider to be quite disgusting.
Especially in a zip-top bag, once the bag is frozen, the plastic becomes stiff and unpliable. Although the moisture content within the bag would normally be in constant equilibrium, once you start shuffling through the freezer, plastic zip-top bags can fracture and create tiny holes that allow dry air in, and moisture out. This is also the reason why most freezer bags leak once you pull them out of the freezer.
Once the zip-top bag has a few nicks and dents, freezer burn will quickly form in the vicinity of any holes in the bag, as moisture is allowed to sublimate and simply leave the bag through the tiny holes, to form ice crystals on the inside wall of your freezer!
As the moisture leaves, the food left behind is destroyed on the cellular level, making it tough, stringy, and unpalatable.
Typically, you either need to cut off freezer-burned portions, or throw away food that has become severely freezer burned.
Freezer burn can start to form in as little as 3 months, and by 12 months, the food in question is probably ruined.
2. Vacuum Sealing
If you vacuum seal your food, this removes air, reducing air pressure and preventing sublimation. The plastic liner used for vacuum sealing is much thicker and tougher than a freezer bag, and thus, the food will last a lot longer.
Vacuum-sealed food lasts much longer – up to 2 years.
3. How to Prevent Freezer Burn
Freezer burn forms when food is exposed to air inside the freezer, which allows the moisture in the air to sublimate and then migrate elsewhere, leaving behind stringy, nasty food.
This is one of the main reasons that the grocery store packaging for most meat products is not your friend. It’ s better to re-package them in a zip-top or vacuum-sealed bag before freezing.
3.1. The Trick to Keeping Food Forever
The trick is to pack your food, especially meat, in fat or liquid before it freezes.
This eliminates contact with the air, preventing sublimation.
- Make sure there are no internal air pockets. Even though the moisture level is kept in equilibrium, internal air pockets can allow food to shed moisture over time (ice crystallizes elsewhere), leaving the food with a tough texture and stale taste.
- Put the food in a zip-top bag.
- Add any of the following:
- Olive oil or some other fatty oil that will eventually congeal.
- Cover in butter or some other fat
- Make sure the food is covered completely, and squeeze out all of the air as you seal it.
- Cooking oil, vegetable oil, and other non-fatty oils remain liquid, even at freezer temperatures. This means that over time, your zip-top bag can take damage, and the oil can leak out, leaving a greasy mess in your freezer.
- If you use a brine or marinade, reduce the salt content. Everything freezes from the outside to the inside. As the bag of brined / marinated food freezes, the water in the brine crystallizes, forcing salt and other elements further in to the food, making the flavor much more concentrated. What you would consider to be a “normal” amount of salt for a brine or marinade can easily result in the food being way too salty when you thaw it later.
One trick is to simply add 50% water to a brine or marinade.
- As meat freezes, ice crystals form inside the meat, which destroys the cellular structure. Later, when you thaw it out and cook it, the meat can be dry and tough as a result. If you freeze meat in a bag of oil, brine, or marinade, the larger ice crystals form at the edges of the bag, in the liquid surrounding the meat, whereas the ice crystals that form inside the meat itself are much smaller, because the meat is further from the air interface, and the rate of freezing increases over time. This means that your meat, if frozen properly, will come out much more tender and juicy once thawed, drained, and cooked.