How To Heat Seal Mylar Bags [5 Steps]

One packaging material that can store food long-term is mylar—a kind of PET material that can be turned into food-grade bags or pouches for long-term food storage. You've probably heard of them before and maybe you've wondered how to seal these bags to keep food fresh. We've discovered how to seal Mylar bags so that your food stays fresh.

How To Heat Seal Mylar Bags

  1. Scoop your dry food inside the mylar bags.
  2. Make sure to leave some space on top to seal the bags.
  3. Place a packet of oxygen absorber inside the mylar bag. Make sure to stuff it inside the food.
  4. Using a cheap hair straightening iron, run the iron across the top of the bag to completely heat seal the mylar bags.
  5. Store your repackaged dry food in the pantry or cupboard.

Using mylar bags for food storage is perfect because the food is well-protected and preserved in this packaging. If you are looking into using mylar bags for your food storage, you're in luck! We've researched the best ways how to seal mylar bags, as well as the kind of food you can keep so do keep on reading this article to learn more.

hand holding Aluminum foil bag Plastic Laser Mylar Foil Zip Lock Bag isolated on white background - How To Heat Seal Mylar Bags [5 Steps]

How To Heat Seal Mylar Bags

Mylar packaging containers

Mylar bags are packaging materials made of layers of stretched polyethylene terephthalate (or PET). They are used for storing dry food for long-term use because of their durability and ability to keep food fresh for very long periods of time.

Typically, mylar bags are silvery and shiny, and they are thick when you hold them. This is because mylar bags are made to protect dry food from moisture, light, and insects from ruining your stocked food.

It is also a packaging material that you can use to repack bulk food items so you can store them in your pantry for a long period of time.

When using a mylar bag, it is important to have an oxygen absorber inside the bag to prolong the shelf-life of the food inside. These oxygen absorbers prevent the oils from the food from becoming rancid, and it also stops the growth of fungi growing in the food.

Get these oxygen absorbers on Amazon.

A mylar bag is also sealed shut by using heat on the top seam of the bag. This can easily be done with a hair straightening iron that you may already have at home.

If you will be using mylar bags a lot and you will be repacking and sealing regularly, then it would be better to get an impulse heat sealer. This will make sealing your mylar bags a lot easier.

Check out this impulse heat sealer on Amazon.


  • Mylar bags
  • Cheap hair straightening iron (or impulse heat sealer)
  • Oxygen absorber


  1. Re-pack your food by scooping it inside the mylar bags you will be using. Make sure that everything is clean and dry when re-packing the food items.
  2. When packing the food in the mylar bag, make sure to leave extra space on top so you can seal the edges of the bag. A good headspace of about two inches should be enough for you to be able to heat seal the mylar bags properly.
  3. Place your oxygen absorber inside the mylar bag with your food. Depending on the volume and size of your bag, check with the packaging of the oxygen absorber to know how many packets you should put in. Do not worry if there is still air inside the bag because the oxygen absorbers will remove all the air inside.
  4. Setting the bags upright, turn on the straightening iron to preheat it to the highest setting. When it is hot enough, run the iron across the top of the bag to seal the bag completely. Alternatively, you can use an impulse heat sealer for this step. Simply place the open part of the bag on the impulse heat sealer and clamp it down to seal the mylar bags.
  5. You can now store your repacked food in your kitchen cupboards or pantry.

What Food Can You Store In Mylar Bags?

Candy/Chips bag

Mylar bags are great to use if you plan to keep dry goods for emergencies or if you simply need to repackage bulk quantities of dry food. These bags can generally keep most dry foods, but oxygen absorbers are required to extend the shelf-life. Here are some examples of the food that you can store inside a mylar bag.

Get these mylar bags on Amazon.


  • Chips
  • Dry biscuits/crackers
  • Candy
  • Granola
  • Dehydrated meat or jerky


  • Brown rice
  • White rice
  • Buckwheat
  • Quinoa
  • Oats

Dry ingredients

  • Flour
  • Salt
  • Sugar
  • Baking soda/powder
  • Cocoa
  • Dry pasta
  • Powdered egg
  • Wheat flakes
  • Spices


  • Powdered milk
  • Powdered juice
  • Instant coffee
  • Cocoa mixes
  • Tea (bags or loose)


  • Beans
  • Chickpeas
  • Lentils
  • Peanuts

How Long Does Food Last In A Mylar Bag?

Most food that is stored in a mylar bag will be kept fresh longer than its usual shelf life. However, there are certain foods that will last longer in a mylar bag, while there are others that are simply not suitable for this kind of storage.

There are different shelf-life for different foods so it would be best to keep an eye on them regularly.

Food high in fat like nuts, chips, chocolate, and other similar food will not last for over a year in a mylar bag. The oils from the food will turn rancid regardless of how it is stored.

Dried meats, fruits, vegetables, and crackers will last for about one to three years in a mylar bag. Powdered milk, cornmeal, and spices can go longer for about three to five years in storage.

Dry grains and beans can go anywhere from five to 20 years if stored properly in a mylar bag. Other items such as sugar, salt, and baking powder/soda can last indefinitely as long as the mylar bags are not punctured and is stored properly.

Are Mylar Bags Different From Vacuum Bags?

hand holding Aluminum foil bag Plastic Laser Mylar Foil Zip Lock Bag isolated on white background.

As we've discussed earlier, mylar bags are opaque packaging materials that are meant to keep food fresh by preventing light and moisture from reaching the food. It is heat-sealed with an oxygen absorber packet inside which ensures that the dry food is going to have a long shelf life.

Mylar bags are particularly used mostly for dry food and for dry storage. It cannot keep wet ingredients or food.

Vacuum bags, on the other hand, are very different from mylar bags. These vacuum bags are typically transparent and it lengthens the shelf life of the food by vacuuming the air out of the bag. Unlike mylar bags, vacuum bags can store wet items like meat and fish, and they can be stored in the freezer.

These two bags are used for completely different reasons. Although they are meant to make the food's shelf life longer, you should consider the length of storage and where to store it before deciding which is best for you to use.

Final Thoughts

Mylar Foil Bag Filling Machine in Food Factory

Mylar bags are great packaging materials that you can use to store dry goods for emergency purposes or long-term storage in the pantry. It is easy to use and it can be sealed quickly with just the use of your hair straightening iron. It's an effortless way to store and extend the shelf life of your food without the hassle of accidentally wasting improperly stored food items.