The air we breathe contains vital oxygen, essential for life. Oxygen is highly reactive, causing oxidation in contact with substances. This is seen when enzymes brown apples or meats turn rancid. Long-term food storage requires removing oxygen, done by using absorbers containing iron powder that reacts with oxygen, creating heat. The process stops once oxygen is absorbed. Airtight containers are crucial to prevent oxygen from returning. Vacuum sealing, combined with oxygen absorbers, is another effective method.
#2 BACTERIA, YEAST, MOLD, & ENZYMES
To extend food shelf life, enzymes need denaturing, and yeast and bacteria populations must be minimized. To prevent microbial consumption and toxin formation in food, we use acidification, salting, and pasteurization to create an inhospitable environment. Acidification from vinegar or lactobacillus fermentation generates acidity, deterring harmful bacteria. Salt extraction removes water, inhibiting bacterial growth and killing some. Pasteurization, through heat, eliminates or deactivates harmful microorganisms with varying temperature-time requirements. “Low temperature, long time” pasteurization at 145 degrees reduces yeast and bacteria and denatures enzymes, minimizing their impact. These methods are often combined for effective food preservation.
#3 LIGHT
Light is also an enemy of long-term food storage. Light causes food spoilage by decomposing chlorophyll, promoting the oxidation of nutrients and the development of bacteria. To prevent light-induced spoilage, storing food in a cool, dark place is essential. Store food in an opaque container and in a dark place to minimize or eliminate light getting to the food.
#4 MOISTURE
Many chemical reactions, bacteria, yeast, and enzymes rely upon water. So, if you reduce the moisture content of the food, you slow or stop all of these processes. Drying food is probably the oldest method of food preservation. This can be accomplished by gently heating the food to evaporate off the water and dehydrate it. Dehydrating food sheds 75-95% of the water. Modern methods involve freeze-drying which gently warms the frozen food in a vacuum environment resulting in 95% or more of the water directly sublimating out of the food as a gas. This is one of the reasons freeze-dried foods have an effective shelf-life of 25 or more years when coupled with other storage methods like oxygen, moisture, and a light-free environment.
#5 TEMPERATURE
The final enemy of long-term storage is temperature. Once the other factors have been dealt with, maintaining a stable temperature is key to a long shelf-life. Bacteria and other microorganisms grow faster at higher temperatures, so storing food at a cool temperature can help to prevent spoilage. Temperature changes encourage the remaining bacteria to do what it does best–survive. For this reason, long-term food storage in a pantry should be at a temperature, ideally 50 degrees or lower, and never changing. The closer you are to 50 degrees or lower, the longer your stored food will last. If you have ever wondered how archeologists could eat grain stored in ancient tombs or drink wine from bottles recovered from shipwrecks on the ocean floor, it’s because preservation techniques were applied to the food, and the temperature barely fluctuated over thousands of years.
IMMORTAL FOODS (ALMOST)
So now we discussed the enemies of long-term food preservation; let’s discuss food items you want to store and the proper preservation and storage methods that allow them to outlive any average human. Here are a few, along with the reasons.
HONEY
Honey contains several compounds that contribute to its natural longevity. Low water content, high sugar concentration, acidity, and the presence of enzymes and other bioactive compounds create an environment that is inhospitable to many bacteria, making it difficult for them to survive and reproduce. It’s mainly the low water content, typically between 17 and 20%. Honey is hygroscopic, meaning it will pull moisture from the air. All the conditions are right in watered-down honey for the spontaneous growth of bacteria and yeast, so you want to store it in airtight containers. If you add water and wait, you will end up with mead, perhaps the oldest-ever fermented alcoholic beverage. In its low moisture state, however, it has been historically applied to wounds to accelerate healing and for its antimicrobial properties. Honey that dated back 3,000 years and was found in Egyptian tombs, when analyzed, was found to be still edible.
SUGAR
Like honey, sugars low moisture content and density provide it maximum shelf life. Sugar is also hygroscopic, like honey, which will pull moisture from the air. This is why sugar left out in the open air will clump and harden. It will outlive you if you store it in an airtight container, moisture free, and in a cool location.
SALT
Technically, salt isn’t food. It is a mineral. It’s used as a seasoning and food preserver. In our bodies, it helps regulate fluid balance, nerve function, and muscle contractions. The moisture content of salt, or sodium chloride, is less than 1%. As a mineral, it can be found in rock form. The combination of low moisture, density, purity, and lack of other substances make it inconducive to bacteria and yeast growth. Note that iodized salt will lose its iodized quality after 5 years, but the salt is still safe to consume. Salt will be around millions of years after we are all gone. Just store it in a moisture-free environment.
HARDTACK
Imagine the hardest, most inedible, flavorless biscuit possible, and you will have hardtack. We made some in a previous video I will link to. The plus of hardtack is that it’s a means to store flour for other purposes. Simply rehydrate the biscuit in water for several hours or days or powder it back into flour for other uses. The absence of moisture and resistance to air and moisture because of its density give this food a shelf life of a hundred or more years. Hardtack is on display in some museums that dates back over a hundred years.
POPCORN
While corn pollen fossils have been found as old as 80,000 years, what we know as modern popcorn was known in China, Sumatra, and India for at least 5000 years. Nobody knows the oldest unpopped kernel ever to be popped, but popped corn has been a food source for thousands of years. Popped popcorn and kernels 5600 years old have been discovered in New Mexico. What allows popcorn to pop is the moisture that builds up to explosive levels inside an outer shell that is so tooth-chipping hard it is almost impervious to moisture and air. Over time, its ability to pop may be lost, but the food is still consumable for years. It can easily be ground or pounded into cornmeal. Store popcorn in an airtight, even oxygen-free environment, and it will outlive all of us.
WHOLE GRAINS
White rice, spelt, oats, wheatberries, farro, millet, rye, quinoa, kamut, and similar hard kernel grains in their whole form can attribute their long storage life, like popcorn, to that hard outer shell. Some will easily last 25 years or longer if stored properly in an oxygen-free environment. They are so hard that they require soaking and cooking or being pounded or ground into flour before being consumed. Storage longevity will depend on oil and fat content, but these have an incredible shelf-life when properly stored.
LENTILS & BEANS
Again, think of the super hardness of the item as part of its resistance to moisture and air and, thus, part of its natural preservation. When properly stored, beans, lentils, and other dried legumes can outlive us all. Discovery of quantities of peas, fava beans, chickpeas, and lentils at Neolithic sites in the Middle East point to their prominence in the diet of early sedentary peoples. Beans aren’t timeless, unfortunately. Every year they age, the less likely they will cook into a tender form. They will be edible for years and years if stored properly, but they will need to be powdered into flour or cooked for a very long time to become edible.
FREEZE-DRIED FOODS
Dehydrating foods extend their edible life, but freeze-drying and properly storing foods will give them a shelf-life of a decade or more, with an average of around 25 years. As the moisture content is reduced to 5% or less, it gains an incredible shelf life of a quarter century or more. The average usable life for frozen food is about two years, canned food up to 3 years, and dehydrated up to 4 years. Another significant upside to freeze-drying is that the process happens so fast that the food’s nutritional content and cell structure are primarily maintained. When the food is rehydrated, even years later, it is often indistinguishable from its fresh form. Freeze-drying is the catch-all for creating immortal foods because any vegetable you can think of will gain a 25-year storage life when freeze-dried and appropriately stored in airtight, oxygen-free containers like mylar bags.
When it comes to long-term food storage, consider and combat the enemies that would eat or spoil your food before you can eat it. Practice your own good preservation and storage techniques. Remove as much air as possible from any container you pack using a vacuum sealer and oxygen absorbers. Label the container with the date you packed it and the type of food. This will help you track how long the food has been stored. Always store the food in a cool, dry place. Remember that heat and moisture can speed up the spoilage of food.
Hopefully, you have a better understanding of why food goes bad and some idea of foods that will have a naturally long storage life. While you can’t survive solely on a block of salt or sugar or a large container of honey. You can use these almost immortal foods along with other grains, legumes, and freeze-dried foods to store food away that could outlive us all.
As always, stay safe out there.
LINKS:
How to Make Yeast From Scratch (DIY) with a Potato
How to Pickle Food: A Beginner’s Guide
How to Make Mead (explained in 60 seconds)
How to Make Hardtack (Forever Lasting Bread)
How to Make Freeze-Dried Taco Meat (25-year shelf-life!)