Preserving food requires the proper containers. Sure, you can throw rice into a Ziploc bag and squeeze all the air out, but that won’t last you for a very long time. First, to understand the value of Mylar bags, you need to understand what causes foods to break down and go rancid or rot.
These are some of the things that cause an undesirable break down in foods:
How Does Air Spoil Food?
Air causes “oxidation” which is when oxygen interacts with the food and causes the transfer of electrons. If you have ever seen rust on metal, you’ve seen the effects of oxidation. When oils undergo oxidation, the result is rancidification.
Another common way that air spoils food is more indirectly: microorganisms. Many microorganisms need air in order to live, just like us. There are also anaerobic microorganisms which must be killed by other means (acidity, heat, etc).
How Does Light Spoil Food?
Have you ever heard the term “sun faded” or seen a child’s toy left outside for too long and the color on it is faded? This is what is referred to as “photodegradation” and it happens to your food as well. But you don’t need to leave it in the sun specifically, light does this in general. If your food is exposed to any light at all, then photodegradation will occur. The amount of light determines how quickly the food will noticeably break down.
How Does Heat Spoil Food?
Heat can do a number of things such as make microorganisms more active and it also speeds up chemical reactions, such as oxidation.
How do microorganisms spoil food?
They eat the food and they expel their byproducts back into it. This can result in an ever increasing spoilage as the byproducts can also contribute to food breakdown.
Additionally, ingesting these microorganisms can make you very sick or even cause death. A well-known illness is botulism which is caused by the bacteria Clostridium Botulinum (which is anaerobic, by the way!).
How Do Mylar Bags Help Protect Food?
Mylar bags create a barrier between your food and your environment. A good Mylar bag will help keep light and air out as well as help shield food from heat, to an extent. Now, Mylar bags won’t protect your foods from microorganisms and heat completely which is where other items and methods come in.
It is common practice to include an oxygen absorber in the Mylar bag before it is sealed. Additionally, the food should still be stored in a cool, dark, dry place to help ensure that no other factors can cause food spoilage. Some people even like to store their Mylar packaged foods in buckets to help prevent punctures and light exposure.
Choosing Good Mylar Bags
So, what Mylar bags are good for food storage? You obviously want Food Grade bags, but they need to be of a good thickness (measured in “mils”). If you can hold your bag up to a light, and see the light passing through the bag, then it is too thin! 4.5 mils is the suggested thickness, but I really prefer thickness over 5 mils. Thicker bags are also more durable and less prone to punctures.