The old adage “You are what you eat” is more important these days than ever before in human history. Everything you put into your body plays an integral part in the general health and overall well-being of that body. The only sure way to guarantee the quality of that food, is to grow as much of it as you can.
Preservation is paramount to a year-round supply of food. Usually, when something in your garden is producing, it gives you more than you need, and yet it won’t stay fresh for long. The trick is make these harvests last longer than would naturally.
There are many ways to preserve food, but the easiest methods for the self-producer are refrigeration, drying, and canning.
Refrigeration is one of the most used methods of preserving food. It consists of keeping food chilled, which delays the decomposition. But wait a second, don’t refrigerators and freezers use an enormous amount of energy? The answer to that is a resounding maybe… like most things, it depends on the design of the appliance.
Your standard upright, 110 AC, compressor powered refrigerator/freezer will probably eat you right out of your energy efficient status. However, a chest freezer/fridge can save you over 50% in energy requirements. Why? Because of the design and the inherent nature of cold air. Cold air moves down, so every time you open an upright design, your cold air spills out of the box, and requires additional input to re-cool the interior. With a chest design, every time you open the box, very little cold air escapes. This is an easy concept to test. Open your fridge while wearing no shoes. Can you feel the cold air rushing out? That is wasted energy pouring onto your feet.
Another concept is timed energy consumption rather than the standard on-demand energy use. Refrigerators have a thermostat installed to tell the compressor pump when to turn on. When the temperature inside the box rises above 40 degrees, the compressor kicks on and cools the box down. As the temperature approaches 35 or so, the compressor turns off. At first glance, it appears to be a fairly good system, but in actuality, it wastes a lot of energy. The reason for this waste is that every time you start a motor (compressor) you must apply extra energy to initiate the turn, breaking the stationary inertia. This is called a surge, and some motors require a substantial surge to get them moving. The surge itself doesn’t use all that much energy because it is short-lived. However, if you start and stop a motor repeatedly throughout the day, then the surges add up, and you end up using a lot of extra energy.
The alternative approach is to time the motor to run for a set amount of time. So, for example, you start the motor at 9 am, and it runs until 10 am. You only have one surge during this time, and the box gets progressively colder as time wears on. Then, you start the compressor once again around 1 pm and run for another hour. Then once more right before night. All in all, you have only 3 surges a day versus the normal 60 or more with a thermostat control. You achieve the same end result, but use less power.
So, for the off-grid power system, you want a chest design with a timed compressor. Or you can use a heat based system instead of the conventional pressure-based system. A propane refrigerator works on this principle. Heat one end of the system, and cool the other end. Your heat can be a different source than propane, like solar thermal, geothermal, wood fire or any other heat source. For more information on these systems, do some research on the zeolite system, ammonia absorption, and solar ice-maker.
Dehydrating food is very simple. You cut the food as thin as possible, then lay it out where it can get good, dry air flow. Keeping the bugs off is another good idea. A screened box with trays is a great design, but there are many other designs that use the sun to dry the food faster.
The best foods to dry are those with a low raw water content. Any food can be dehydrated, but ones that have low water content to begin with will dry faster. Squash, beans, apples, bananas, peppers, eggplant, and pumpkin are good driers. The goal with drying is to dry the food as fast as possible to avoid nutrient loss or rotting. Drying is not limited to veggies, and is a good way to preserve meat. Salt the meat and cut it thin. Keep the flies off of meat! They will bring in rot-causing bacteria.
One of the great advantages with drying food is that you preserve a lot of the original nutritional content. Every time you heat or cook food, you lose something of its value.
If you’re interested in dehydrating food, chick out our solar food dryer instructions.
Canning food is a popular traditional method of preservation. Although it requires energy, the nutritional value is well preserved, and most foods can be stored for quite some time (years) with this method.
The problem with canning is that it can be extremely dangerous if done incorrectly. There can be various kinds of bacteria, molds or yeasts present naturally in your food, however the most common danger is considered botulism. Although this bacteria is killed easily by heat and won’t grow when cold, its spores are extremely resilient.
Canning safely depends on how many micro-organisms are in the food to begin with, not using too big of a can (as the center can resist the heat better than the extremity), acidity of the food (high acid kills spores), the temperature reached and for how long.
To avoid the possibility of poisoning yourself and your family, it’s a good idea to read up on the dangers of canning before you start the process – it is well worth the effort!!
This method is used only for fruits and high acid tomatoes.
If you are canning low acid foods such as meat and vegetables, you will need a pressure canner, as it must be heated to 240°F to kill botulism spores. Follow directions for your particular pressure canner.
There is a reason older homes always had a root cellar. There are many vegetables, and even fruits, that will store well without doing anything to them. All they need is a cool, dry, and dark, place to hang out until you’re ready to eat them.
For the storage of some of this type of produce, you will want to avoid the items touching each other. Others, however, this isn’t such a big deal.
Winter squash, like pumpkins, acorn and butternut squash, last a long time. Most root vegetables, like potatoes, sweet potatoes, garlic, onions, and beets will also store well.
You can always experiment with some of your produce and see how it does. Worst comes to worst, it’ll end up chicken or pig feed.
Fermentation is an ancient technique for preserving and enhancing nutrients in food. From alcohol production to sauerkraut, there are many ways to use yeast and bacteria to help us preserve our food. Lactic-acid fermentation is a common method for vegetables. This is the traditional way of making pickled vegetables.
The way fermentation works is that beneficial bacteria or yeasts digest part of the food, and in doing so, produce waste products that prevent rot-causing bacteria from surviving. We can give our good guys a head start by adjusting the salt levels or ph to make conditions for their growth right from the start.
Lactic-acid fermentation usually starts with making salt brine and soaking the vegetables in this brine. As long as the vegetables are completely covered in the brine, they won’t rot. The salt kills just about everything, but a special group of bacteria, Lactobacillales, use the salt to produce a low-ph solution that tastes sour (like vinegar). Lactobacillales thrives in the high salt, low competition environment and ferments the food, preserving it with their solution.
Fermentation has the added benefit of probiotics and pre-digestion. These features make fermented foods not only tasty, but healthy to boot.