The purpose of this article is to present specific details and
recommendations for packing your own shelf stable foods for food storage, including
what works and what doesn't in creating an oxygen free atmosphere for long term
food storage, and the common misconceptions of how to do your own packing will
be covered. While there are many different types of dried foods that can
be stored for extended periods of time, most folks are interested in how best
to store grain and bean products.
Some material will be repeated in this article that has been covered in
previous articles concerning the use of oxygen absorbers, storage conditions,
and 30 year shelf life claims. While I could write a book on every
specific detail of every packing option and all the technical specifications of
all available packing containers, it is not the purpose of this article.
I will cover important highlights, facts, insights, and information gained from
over 47 years in the preparedness and outdoor recreation industry. It is
important to keep in mind that I have not only been a retailer of preparedness
and outdoor foods, I have been a manufacturer, developer of hundreds of
recipes, packaging and product innovator, and researcher of shelf stable
foods.
Some of the material presented here will contradict and challenge
information available on the web or in some do-it-yourself circles. Many
people assume preparedness information to be accurate without careful
consideration of the expertise of the source or the validity of the
facts. I encourage you to research on your own any of the information
presented in this article - or in any article for that matter - and to use
basic critical thinking skills to evaluate the evidence and data you are
offered. A little common sense goes a long way in assessing many of the
claims being made about shelf life and do-it-yourself issues. I talk
about the issue of trust and reliability in my articles: Who do you Trust?, The Research and Evaluation Process, and Purchasing Food Reserves - The Essential Questions.
Basics:
Before you start packing your foods, be clear about what it is you want to
store and for how long. Are the foods appropriate for your plans?
Do you know how to prepare them? Do you have an adequate quantity?
Do you have all the equipment necessary to prepare your foods? What is
the nutritional quality? I suggest you study the key foundational
information in my article Beginning and Improving Preparedness Planning.
This is an article dealing with dry food products with a low to very low
moisture content - depending upon the item usually between 2 and about 10
%. Products can include grains, beans, seeds, dehydrated or freeze-dried
fruits and vegetables, seasonings, and powders and flours.
Grains and beans can be whole or processed into numerous forms. Keep
in mind that when a whole grain or bean is processed it can compromise the
integrity of a natural barrier, expose any oils, and begin a process of
oxidation or rancidity leading to a shortened shelf life. Some processed
bean products, such as TVP (Textured Vegetable Protein) have been defatted to
insure a longer shelf life, and some grains have naturally lower oil
content. Because of the position of the germ in rice, brown rice is not
appropriate for long term storage. Also, because white flour has no wheat
germ, it will last significantly longer than whole wheat flour. Research
the products you are storing to determine both the moisture and oil content.
What are the goals and expectations for your food preparedness
planning? What are you hoping to accomplish and for whom and how
many? How realistic are your plans? How long do you want your
stored foods to be palatable - edible - nutritious - agreeable? Be
honest. I once again refer you to another very helpful article in assisting
you in preparedness planning
: The 12 Crucial Questions of Preparedness Planning.
Why oxygen free?
At the end of this article I have included information on the 6 critical
conditions for storing food. In this section we explore the need for an
oxygen free atmosphere when storing food for long periods. Basically
there are 2 reasons for wanting to store food in an oxygen free environment -
eliminate the possibility for infestation from insects and microorganisms, and
control oxidation, which leads to the rancidity of fats and oils, foul taste,
off color, and nutritional deterioration. The lower the oxygen levels -
the more effective in preserving the integrity of the foods stored. Some
foods are more susceptible to oxidation deterioration than others. It is
important to know how susceptible the foods you are storing are to oxidation,
because as you will see the type of container you store your foods in may at
some point no longer be an adequate oxygen barrier. Research by
Mitsubishi Gas Chemical Company, the inventors of oxygen absorbers and
manufacturer of the Ageless® brand absorber, indicates that in an oxygen free
atmosphere (their absorbers can reduce the residual oxygen level in the proper
container to 0.1% or less) all adults, larvae, pupae, and eggs of the most
prevalent dry food insects are killed within 14 days.
If oxidation and elimination of all stages in an insect's development by
eliminating available oxygen is not an issue, there are other methods that can
be utilized with varying effectiveness in controlling insect infestation.
Options include:
Exposure to freezing temperatures for an adequate length of time
Using bay leaves and other aromatic herbs to inhibit insect reproduction
Using food grade diatomaceous earth to kill adults (the microscopic very sharp
texture of the particles pierce the bodies of the insects and they dehydrate
and die). In this case the live adult must come into contact with the
diatomaceous earth. Some folks put the material on the bottom of a
container hoping the insects will go there, while others coat all the contents
of a container with a fine layer of material and wash it off when it is time to
consume the food.
Methods of reducing residual oxygen levels
when you pack your own
Very effective in reducing residual oxygen levels - in my opinion it is the
most effective technology available today.
Relatively inexpensive and easy to use if done properly.
Harmless components - iron oxide.
Easily obtainable.
Con:
This product was developed for use by professional food companies who
understand how to properly use and store it. There are important
guidelines which must be followed for the absorber to work properly and not
lose its effectiveness. The do-it-yourself person will defeat the purpose
of using this technology if the guidelines and instructions are not properly
followed. It is imperative that the absorber user obtain all necessary
information from a
qualified supplier on its correct use.
The absorber user needs to do their homework and make sure the correct sized
absorber is being utilized for both the size of the container and food product
packed.
Insert a wand into a pouch, can,
bucket, or jar and attempt to replace the atmosphere by squirting it with
nitrogen
(the most commonly used inert gas)
Pro:
Fairly easy to do
Relatively inexpensive
Con:
Without the proper testing equipment there is no way for the pack your own
person to know the residual oxygen levels of their containers. If the
levels are too high, you have defeated the purpose for which you
intended. How much nitrogen to use and the length of time to insert it
into the container are both speculation and assumption. Do you want to
rely on guess work?
When removing the wand and sealing the container some amount of oxygen will
be introduced into the container, which will affect the atmosphere in the
container.
To achieve the desired effect of a very low residual oxygen level this
method has many weaknesses. (
NOTE: Before the days of the oxygen
absorber, companies such as mine used elaborate equipment designed to draw a
vacuum and nitrogen flush in a chamber. The goal was a residual oxygen
level of 2% or lower, because this was the military specification for long term
storage of foods in a #10 size metal can. Even with the proper equipment
reaching these residual levels required experience, testing,and effective
methodology. Can "wanding" by hand achieve these levels?)
The dry ice method: There was a
time (and there may still be) when folks would put dry ice at the bottom of a
container, leave the lid slightly ajar, wait for the ice to evaporate, and then
seal the lid. This method has so many problems that I won't bother to
give it pros and cons. It is not recommended.
Use a home model vacuum sealer with
either a plastic pouch or available attachment to put over a jar
Pro:
Equipment is easily accessible
Can be effective for short term storage
Easy to use
Con:
Equipment and extra pouches can be costly
The vacuum pulled (measured in inches of mercury) may be helpful for short
term use, however is neither strong enough nor effective for a long term
storage requirement. The pouches and jar seams are not designed to hold a
vacuum for extended periods.
Go to a cannery: You can do your own canning of your own
product in #10 metal cans. Some canneries will sell you bulk foods.
Pro:
Very effective method for long term food storage - metal cans are the best
containers
Depending on the cannery, costs can be low for using the equipment
You can easily insert an oxygen absorber into the cans for maximum shelf
life
Con:
While metal cans are the most effective containers, they can be costly
Canneries are not readily available to most folks - most are sponsored by
members of the Mormon Church, check on usage and membership requirements, hours
of operation, and costs at each cannery
You'll need the proper vehicle to transport bulk foods and cans
Use a manually operated or electric,
smaller, model open top can seam sealer
Pro:
Very effective method for long term food storage - metal cans are the best
containers
You have significant flexibility as to when to use the sealer, and with whom
it is to be shared
You can easily insert an oxygen absorber into the cans for maximum shelf
life
They are easy to use once you get the hang of it
Con:
They can be expensive
You must do your homework and determine the best manufacturer and model
You must make sure you are operating them correctly and that the seams are
being sealed properly
You need access to a supply of cans
Containers
Of all the issues relating to packing your own shelf stable
foods, the most effective container to use can be the most confusing and
misrepresented. As stated in the
beginning of this article be clear about what you are storing, how much, and
for how long.
Plastic buckets (HDPE - high density polyethylene) 5 and 6 gallon round and square sizes with
handles are very popular for packing grains, beans, and other commodities in
bulk
Pro:
A convenient container to store larger quantities of dry
foods stores and stacks well, is compact, and can be carried easily.
Inexpensive new and can be obtained used from a number of
sources.
A thick walled (90 mil) container with the proper gasket can
be used effectively to control the atmosphere within for up to 2 to 3 years.
Can be used in conjunction with foil pouches for convenience
of storage.
Insects don't easily penetrate the thick walls.
Can withstand some rough handling.
Because insects at all stages are destroyed within about 14 days,
the short term effectiveness of using an oxygen absorber to create an oxygen
free environment is useful.
Con:
HDPE is a permeable (porous albeit microscopic) material
and gas transmission rates (the length of time gases such as oxygen will travel
through a given material) indicate that it will take 2 or 3 years for the
atmosphere within the bucket to match the atmosphere outside (our normal
atmosphere is normally about 21% oxygen and 79% nitrogen with a very small
amount of other gases such as carbon dioxide).
This means that if you started with an oxygen free or low level to begin
with, that over time the oxygen level in the bucket will continue to increase
until it reaches parity or equality with the normal atmosphere.
If you want the atmosphere to remain constant inside your
container, or be oxygen free for extended periods of time, HDPE plastic buckets
are not appropriate – check with the manufacturers (as I have done) and find
out their specifications and recommendations for your needs and the specific
container you want to use.
The ability to maintain whatever atmosphere you desire
within the container will depend not only on the quality of the HDPE walls, but
also the integrity of the gasket seal.
HDPE will absorb odors and they will eventually permeate
into the contents of the bucket. Direct
packed foods will also absorb the odor.
Do not store plastic buckets in areas that have a strong smell. (NOTE:
Foil pouches within a bucket will prolong the odor absorption)
Rodents and other animals can easily break into plastic
buckets.
Pouches: There
are literally thousands of possible combinations of materials and sizes
available to create a pouch that will contain food. Normally a food manufacturer or packer goes
to a company that specializes in manufacturing pouches and gives the company
their specifications and requirements for the specific foods to be packed.
IMPORTANT NOTE: It is
common these days among those who sell pouches for do-it-yourself food storage, or food
already in pouches, to use the term "Mylar pouch." This is very misleading. By itself the term can mean anything and it
tells you nothing of importance so that you can make the appropriate decisions
on what pouch to use. The Mylar brand is
the registered trademark name of a PET polyester film manufactured by DuPont
Teijin Films. They produce hundreds of
variations of this polyester resin material.
It is a component used in the production of many variations of packaging
material. It can be clear or opaque such
as in wrappers for food bars or Mylar balloons that look metalized yet
contain no foil. Mylar by itself is not
an appropriate material for long term pouched food.
Ask your supplier what they mean when they
say "Mylar".
For those reading this article the requirements are
to pack dry foods for the long term. If
you buy stock pouches from a distributor you need to tell them what you plan to
put in it and what your expectations are for the long term. You should insist on knowing the
specifications (especially the gas and vapor transmission rates) of the pouch
and whether they suit your needs.
If you want a pouch that gives you the longest possible
shelf life for your foods, you will need a laminated pouch consisting of
multiple components and layers. As far
as pouches are concerned, one of those layers must be foil (NOTE: All plastics
are gas and vapor permeable with some transmission rates being very high - meaning that gases
transmit through them very quickly and some plastics both individually and in
combination have slower rates). Only
quality foil is a non-permeable gas and moisture barrier. Providing the foil is without
microscopic holes)
Ask the distributor the specifications of the pouch and the
different components used. What are
the transmission rates if the material is not foil? How reliable are the pouches for your usage?
Pro:
The variety of available sizes offers flexibility in choices
of quantities to store.
Costs are reasonable.
Can be effective as a short term oxygen free container.
Small pouches of food can be very useful for bartering and
distributing among those in need during in an emergency.
Con:
Not recommended for very long term packaging of products for
an oxygen free environment. Shelf life of
pouched foods is recommended for 3 to 10 years depending on type of food
product, storage conditions, handling, and composition packaging materials.
Excessive or rough handling, loss of seal integrity, and
pressure of sharp edges on the pouch from the products within can create pinholes (microscopic holes in the pouch material) that eventually will cause
gases to be transmitted through the pouch (NOTE: I am concerned when I see and
hear some folks instructing people to cram and squeeze foil pouches into plastic
buckets).
Rodents and other creatures can easily penetrate pouch
material.
Metal cans: For
food storage purposes #10 size (about 7/8 gal) and #2 ½ size (about 7/8 qt) are
the most popular used with the proper can sealers. It is possible, if you keep searching, to
find 5 gallon square metal cans with a large pressure lid on the top side. These are ideal for bulk food storage,
although they may be hard to find (NOTE: I sold these cans packed with foods at
AlpineAire Foods about 20 years ago). You
also may want to consider clean or new metal garbage cans as a means to store
smaller size foil pouched foods.
Pro:
Ideal for long term food storage. The atmosphere within the cans, with the
proper sealing, can remain oxygen free indefinitely.
Metal is non-permeable for gas and vapor - a zero
transmission rate.
Difficult for rodents or animals to penetrate.
Can withstand some rough handling.
Con:
Costs can be higher than other materials.
Extra attention must be given to proper sealing.
Some metal containers may be difficult to obtain.
Some cans may rust if exposed to moisture.
Glass:
Pro:
Excellent for long term food storage. The atmosphere within the jars, with the
proper sealing, can remain oxygen free indefinitely.
Glass is non-permeable for gas and vapor - a zero
transmission rate.
Difficult for rodents or animals to penetrate.
Easily obtainable and relatively inexpensive.
Con:
Very fragile - must be stored and handled with care.
Practical only in smaller size containers.
Personal recommendations and tips for long term pack
your own food storage
First choice: If possible store foods in metal cans with
the proper size oxygen absorber
Second choice:
Pack foods in a heavy duty foil
laminate pouch with the proper size oxygen absorber. I prefer using a variety of smaller size
pouches rather than one large pouch.
If you seal the pouch with an iron, as opposed to a commercial impulse sealer, make sure you know the proper
method to use. If your seal isn't
adequate you are wasting your time and money using an absorber.
Place the foil pouches carefully
to avoid pinholing and seam damage, into another larger plastic or metal
container (NOTE: Sturdy cardboard boxes will do if infestation from insects,
rodents, and other animals is of no concern).
This will facilitate handing and storage.
When you use the proper size oxygen
absorber in a foil pouch it will create a slight vacuum and the pouch will
tighten up somewhat (Remember you are not creating a complete vacuum that would
produce a brick hard pack, you are only removing about 21% of the air volume -
it will be absorbed by the iron oxide in the oxygen absorber sachet).
Periodically, especially in the
first two weeks, check on the pouch to make sure it still looks tightened
up. If at some point it looks normal,
then the integrity of the pouch has been compromised and the atmosphere in the
pouch has equalized with the outside atmosphere.
I see no point in putting additional oxygen absorbers into
the plastic bucket or container in which the foil pouch is placed.
I do not recommend using the nitrogen wand method of
atmosphere replacement in pouches, plastic, or metal containers if you want to
create a truly oxygen free environment.
The oxygen absorber properly used is the best method for
creating an oxygen free environment.
Certain foods packed for long term storage may not need an
oxygen free atmosphere. I have covered
the reasons for creating this type of environment earlier, and your specific
needs may focus only on containers and storage conditions.
I do not recommend storing commodities in their original
paper or cloth sacks or boxes for the long term unless you possess a very
secure and unique storage facility. The
important issue here is infestation and environmental influences such as heat,
moisture, and other airborne contaminants.
Periodically inspect your food reserves for any sign of
infestation or contamination.
There are six conditions to be aware of when storing food for emergency
preparedness food storage, or outdoor recreation. The foods being
referred to in this post are shelf-stable freeze-dried, dehydrated, dried
commodities. Optimal storage conditions can also be applied to wet
pack: retort, MRE's, canned goods, and other specialty longer term wet
pack foods.
NOTE: The six conditions listed are chosen because
these are factors in which we have the control to optimize for the
longest reliable shelf life.
TIME is the one factor
that we can not control - and it does have a significant effect on the
shelf life of various foods. Nutritional value is lost with many foods
over time. To know with certainty the viable nutritional value of all
food reserve items at any given time after a lengthy period of storage
- is at best complex or most likely mere conjecture and guesswork.
What we can do is to apply proper planning procedures - do your
research with trusted resources, rotate and consume your storage foods,
and be realistic about how long you will really need the foods you
choose to store.
Temperature- This is
the primary factor affecting the storage life of foods. The cooler
the better. 40 degrees-50 degrees would be great. Room temperature (65
degrees-72 degrees) or below is generally fine. Avoid above 90
degrees for extended periods of time. The longer food is exposed to very
high temperatures the shorter the edible life and the faster the
degeneration of nutritional value. Note: There are some "foods"
available for emergency preparedness that are known as "emergency
food or ration bars." These products are generally referred to
as "life raft bars" because they were originally designed for
life rafts and can withstand high heat for extended periods of time.
They primarily consist of white sugar and white flour, and were not meant
to be the sole source of nutrition for a long period of time.
Moisture- The lower
the better. Moisture can deteriorate food value rapidly and create
conditions that promote the growth of harmful organisms. The
moisture level contained in foods varies depending on the type of product
it is. Have foods in moisture barrier containers (metal, glass) in
high humidity areas. Note: Mylar bags or plastic buckets are not a
long term (over 3 years) moisture or oxygen barrier. The moisture and gas
transmission rates through these materials vary depending upon the
specifications of the manufacturers. Plastic absorbs gases,
moisture, and odors. Note 2: Be careful where you store dry
foods in cans. Very cold flooring or any condition where there is a
dramatic temperature differential may cause a build up of condensation
inside the container.
Oxygen - A high oxygen
environment causes oxidation, which leads to discoloration, flavor
loss, odors, rancidity and the breakdown of nutritional value in foods. It
also allows insects to feed on dried food reserves. Without oxygen,
insects cannot live, nor can aerobic (oxygen dependent) organisms. Whole
grain and beans have natural oxygen barriers and can store for long
periods of time in low humidity and if free from infestation. All other
processed grains, vegetables, fruits, etc. must be in a very reduced (2%
or less) oxygen environment for long term storage. Note: Mylar
bags or plastic buckets are not a long term (over 3 years) moisture or
oxygen barrier. The moisture and gas transmission rates through these
materials vary depending upon the specifications of the
manufacturers. Plastic absorbs gases, moisture, and odors. The
best long term storage containers are glass and metal.
Infestation - Examples
include rodents, insects in all their stages of growth, mold,
microorganisms, and any other creatures that get hungry - large or
small. The proper packaging and storage conditions are required to
control infestation and not allow critters to both get into the food, or
have the necessary environment for them to flourish if they are sealed
into a container - such as in the form of eggs or spores.
Handling - Rough
handling can not only damage the food itself, but it can also adversely
effect and compromise the integrity of the container in which the food is
stored. Glass of course can break; any pouched item can develop pin
holes, tears, or cracks. The seams on buckets and cans can be
tweaked, twisted, or damaged to allow oxygen to enter the container.
Light - Food should
not be stored in direct sunlight. Both for the potential of high
temperature, and its affect on food value. Sunlight directly on
stored foods can destroy nutritional value and hasten the degeneration of
food quality, taste, and appearance. Foods packed in light barrier
containers do not pose a problem with the affects of light.