Outside of the air conditioner, refrigerators and freezers typically consume the most energy in a house and you will want to eliminate this load in hard times when home-produced power will be scarce. The key is to convert the short-term harvests of summer produce and fall butchered meat into shelf-stable forms for use throughout the year. As I have covered in previous tips dehydrating food is one option, but canned food is almost always easier to use and eat.
Steam canning and water bath canning are practical for acidic foods like fruit and tomatoes but vegetables and meats must be canned at higher temperatures to kill not just bacteria and viruses (eliminated by boiling temperatures) but also the spores of the bacteria botulinum (botulism). Once a food begins to boil it is very difficult to heat it to higher temperatures—the water just keeps boiling off. The solution is to contain the heat and steam in a pressure vessel. Water boils at higher temperatures under pressure.
The best line of pressure canners is still the All-American because of its patented lid shape which does not need a gasket—eliminating a weak point in other models. It also uses the weight on top to manage 5, 10 or 15 pounds of pressure which never needs recalibration like the adjustable pressure gauges on other models. The large 21-1/2 quart canner (model 921) is the best size for most households; it holds 7-quart jars or 19 pint jars and is deep enough to process ½ gallon jars. There are larger models too but they are too big for most stoves and take even longer to heat up.
Despite their versatility over any heat source, stovetop pressure canners are inefficient because they require so much heat energy and time from the operator. They take over 15 minutes to heat up and build the pressure and then you have to watch the pressure gauge as you fiddle with the stovetop burner setting to get and hold the right pressure. It is much more tedious than a steam canner.
The modern electric pressure cookers on the market like the Instant Pot seem like the ideal solution. They use less heat and have a computer to control temperature, pressure and time—a kind of “set it and forget it” canner. What could be better? The problem is that most units are only rated for up to 10 psi and the National Center for Home Food Preservation (NCHFP) wants to see 15 psi for higher altitudes, and has declared that none of the machines meet their approval. Most manufacturers have backed down from any canning claims except to recommend their units for acidic products that are easily steam canned instead.
Many experienced homemakers from a generation ago would likely laugh at these official precautions. Back then households regularly canned even non-acidic products in a steam canner and the incidence of botulism was still very rare. I suspect there are factors that reduce the growth of the botulinum or reduce the effects of its toxins that are ignored by our safety agencies in their efforts to avoid any risk altogether. For instance these safety groups advise throwing out any food bottled by questionable methods, yet the CDC itself acknowledges that simply heating infected food to 185 degrees F (which is still below boiling) for several minutes will neutralize botulism toxins. Non-acidic canned products like meat and vegetables are nearly always heated up in a meal before being consumed. Whereas the jams, jellies and fruit preserves we enjoy straight out of the jar are acidic which naturally impedes the bacteria spores.
Some electric pressure cookers still sell their ability to be used for canning, such as the Carey 9SS model, but if you come to rely on electric canners, get a backup stovetop pressure canner for hard times when electricity may be harder to come by than a hot wood stove. At a third of the cost the Presto 23 quart model is a good backup unit that also uses a weight for pressure, but be careful with it because the aluminum isn’t as sturdy and it has a gasket seal.
The Presto website has current advice for cook times and pressures for different vegetables. The times are easy to figure out once you realize that items with thicker flesh or canned in larger chunks need more time for the heat to penetrate. I am surprised how many products merit the maximum pressure (15 psi) and 90 minutes of processing which is a long time to have your stove on high heat. If you can’t achieve this level of processing in hard times, consider your lower times or pressures that still seal the jars well and pasteurize the contents and write “heat before serving” on the lid. Even less-than-perfect canning will be better than letting food rot when the freezer isn’t working.
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