Hampstead RS Blog

LONG-TERM STORAGE METHODS FOR DRY FOODS
(Storage for longer than 5 years)

    To prepare dry (10% or less moisture) food for long-term storage, oxygen should be removed from or replaced in containers. There are four kinds of containers that can be used:
    1. #10 metal cans
    2. Heavy mylar pouches
    3. Glass canning jars
    4. HDPE plastic buckets

    All four kinds of containers should be stored in a cool, dry and dark environment for the longest shelf-life.

Enamel lined #10 metal cans are filled with dry food, an oxygen absorbing packet is added and the can is sealed with a can sealer.  Cans can be stored in a small amount of space and should be stored where they are not in direct contact with floors and walls.  Cans are impermeable to light, moisture, air and insects, but they will eventually rust when stored in humid climates.  When a can is opened, a plastic lid should be put on it or the contents transferred to a container with a lid.  Each can will hold about 13 cups of food.  Used cans cannot be reused for canning without using a reflanger to cut and reshape the edge of the can.

Heavy mylar pouches are filled with dry food, an oxygen absorbing packet is added and the pouch is sealed with an impulse sealer.  Pouches that are 7 ml thick are not easily punctured but can still be chewed through by rodents.  The pouch is impermeable to light, moisture, air and insects.  They can be slid into shorter spaces than #10 cans, stacked in boxes or bins, put in plastic buckets, or placed on a shelf.  Pouches should not be stored in containers that have been used to store nonfood items.  Once the pouch is open, the contents should be transferred to another container with a lid and stored on a shelf or in a cupboard.  The 12” by 13-1/2” pouches comfortably hold 1 gallon (16 cups).  Used pouches can be washed, dried and reused but will hold less food each time they are reused.

Glass canning jars are filled with dry food, an oxygen absorbing packet is added, the jar edge is wiped clean and a new, clean canning lid and ring are screwed on tightly.  Glass is impermeable to moisture, air and insects. Jars should be stored away from light and in a way that protects them from breakage.  They can be stored in a short space such as under beds.  Once opened, jars are usually small enough to store in a cupboard or on a pantry shelf where the contents are easily seen. When the jars are reused, a new lid should be used.

Because food grade HDPE (high density polyethylene) plastic buckets are oxygen permeable, dry food must be packed in one of two ways for long-term storage.

    1. A thin mylar bag is placed inside a clean bucket, the bag is filled with food and oxygen absorbers are put in (one 300 cc absorber for each gallon of food). The bag is sealed by placing a wood board on one edge of the bucket, folding the top of the mylar bag over the board and ironing the bag until it is sealed. The top of the bag is then folded into the bucket. The bucket lid is secured by hammering around the outside edge with a hammer or mallet.  The commercially prepared version of this is sometimes called a “super pail.”
    2. A 2 to 3-inch layer of food is placed in the bottom of a clean bucket and dry ice is added (2 to 4 ounces for 5 gallons). The bucket is filled with food to within 1-inch of the top and the lid loosely attached. The dry ice is allowed to sublimate (change to gas) for about 30 minutes or until the bottom of the bucket is no longer very cold. The lid is secured and the bucket watched for bulging for a short time. If the lid or sides bulge, the lid should be lifted slightly to allow gas to escape and then resealed. When the bucket no longer bulges, it is safe to store.

Buckets should be opaque (especially when using dry ice since they are not lined with mylar) to protect food from light. They should be new or, if used, should have stored only food previously. They are impermeable to moisture and insects when they have a gasketed lid. When packed using one of the above methods, they also protect from the air. To open buckets, cut through the marked slits on the sides of the lid (being careful to avoid cutting the gasket) and pull up sections until the lid comes off. Lid lifting tools are also available. Some lids have a round opening with an attached spout and lid for pouring out the contents without removing the main lid. Frequently used buckets can have the lid replaced with a gamma seal lid (a 2-piece lid with a removable inner portion) for ease of use.

Buckets should not be stored directly on cement. They should rest on racks or pieces of wood to allow air to circulate underneath and prevent the cement from sweating. Avoid stacking them more than 3 high especially without boards between the layers or the center of the lid may crack and break.

For additional information, visit the home storage pages at www.providentliving.org

NOTE: Sugar should not be packed with oxygen absorbers.

Home Preservation of Dried Foods and Grains By Dr. Albert E. Purcell, Research Associate, Department of Food Science and Nutrition, Brigham Young University