Freezer burn is simply drying of food in the freezer. But there is of course plenty to know about the causes, prevention and science behind the process. If you are consistently experiencing freezer burn in your freezer this article will help abate the process.
Freezer burn is caused by drying of the product in question. Usually you will see this most prominently on the surface of meats. The reason it is so easy to see in meat is the oxidation that occurs as an effect of the drying. We will talk about that later. One thing to realize about drying in a freezer is the product does not have to come above freezing to experience drying. Sub freezing drying is referred to as sublimation which we will also cover later.So if your products are experiencing the burn you have a couple thing to ensure to prevent it from continuing.
The first line of defense against freezer burn is air tight packaging. While a perfectly air tight container can prevent freezer burn it can not always stop it. The air tight packaging simply creates a static environment of humidity that prevents water from leaving the solid food and sitting in other areas of the packaging. The freezer itself can also be the problem. If the defrost cycle of the freezer is causing systemic and repetitive temperature changes in the freezer that can also cause freezer burn. If you notice the items on the top shelf are those most often experiencing freezer burn this may be your problem. Move sensitive items to the bottom shelf. If inverse is true and the bottom items seem more affected it could be that you or your team are spending too much time with the door open. In this case close the door. Were you raised in a barn?
Now for my favorite part. THE SCIENCE. We get to discuss sublimation, oxidation and thermodynamics. You have heard all your life the steps for matter was solid to liquid to gas. Well sometimes in the right conditions you can skip from solid to gas. This skip is referred to as sublimation. This is the process used to freeze dry products. Low pressure is used to encourage water from a product which causes it to freeze. Oxidation simply refers to the loss of electrons. This typically causes the loss of an atom and possible chemical change. This presents in meat as pigmentation change. The thermodynamic part of the science is super simple cold goes down, heat goes up and the heat exchanging coil in a freezer is almost always at the top of the freezer. With that information you can infer a lot about what is happening in you freezer.
In conclusion freezer burn is simply drying and to avoid it package your food tight and avoid temperature fluctuations in your freezer. If you need to rent a freezer call RJH.