When learning to can there are certain safety measures we all need to know about to make sure you, (or those around you) do not become injured, sick or seriously scarred. We learn these safety measures through research, manuals, and other canners’ experiences. In this article I am going to give you a sensible argument about why it is unsafe to oven can and why it could be considered an impractical way to store dry goods. We will also discuss alternative methods to storing your dry goods.
Is Dry Oven Canning Safe?
The answer is NO. As Wise Geek so elegantly explains this…
Oven canning is not safe because it is a dry heat and the jars are not made for that. They can explode. Contamination is the main fear when it comes to dry canning. In order for food to be shelf-stable, it must be heated to a hot enough temperature that any latent bacteria in the food is killed off. The premise behind dry canning is usually sound, as a 200°F oven is generally hot enough to be considered sterile. Not all oven thermometers are accurate, however, and it can be tough for home cooks to know whether the external temperature is actually penetrating the jars.
There is no way for cooks to test the internal jar temperature without removing the lids and compromising the food. Any bacteria that remains in sealed jars can grow into toxins over time, which can cause serious food poisoning once the contents is eventually consumed. Sometimes spoiled food looks discolored or has an unpleasant taste, but not always.
Then there is oil. Some of the few things that have oil in them are nuts and seeds and even some flours. The heat from the oven liquefies the oil making the product go rancid faster than if you had left it alone, which defeats the purpose.
Lets pretend you have twenty, 1 pound bags of pinto beans and you want to store them air tight for long-term food storage. Right off the bat you’re going to have to buy, at minimum, two boxes of jars that run about $10-$15 each depending on where you live. (Assuming you do not have them already or have enough.) You will also have the added cost of using your electricity/gas to oven can your food. Depending on how often and how much you can, that can raise your monthly bills considerably.
If you already have a vacuum sealer machine, a 3- 20 foot rolls of bags cost approximately $26.50, however, you will be able to seal and store much more. Something else you might consider is instead of using the jars and the space they take up dry canning, use them for canning meat items and things you can not otherwise vacuum seal (Mmmmm, like salsa). If you insist on storing your dry goods in jars then the safest and cheapest way to go would be to use an Oxygen Absorber in the jar and then use a vacuum seal jar attachment to remove air and seal the jar tightly. If you do not have a vacuum sealer you can still add an Oxygen Absorber and then listen for the *ping* sound we all love about 15 minutes after you tighten the ring. The three most dangerous things you can do to your food storage is expose them to heat, light and moisture. So why expose your food to heat if you don’t have to?
In our home we use storage totes and five gallon buckets to store our dry goods. When we vacuum seal the food in the bags we pack them tightly in a storage tote and once full we place the lid on them and stack them up. I love how light the tote is (depending on the food of course) compared to stacking and moving jars. We typically use the vacuum sealer for items like crackers, drink mixes, tea bags, dried herbs, coffee, etc. For things such as rice, beans, flour, and sugar we use the five gallon buckets with Mylar bags.
As you can see, Dry Oven Canning can be more expensive, take up more space and can be very dangerous, as with any canning that does not practice safe, tried and true practices. Keep your family safe and stick to methods that have been tested and proven safe. One of my favorite quotes: Past performance does not guarantee future results.
Keepin It Spicy,
Some more facts on Botulism and the dangers of unsafe canning practices.
What Research Means
Water bath canning and pressure canning have a higher degree of safety and reliability than dry oven canning. Both styles of canning have been tested, ‘researched’ and if done correctly is safe every time. Food storage is about storing your food safely for you and your family to use in hard times. Medical care may be scarce, getting sick from home canned food is not an option when hard times hit. Food borne illnesses can be mild and sometimes more serious, resulting in death without immediate care.
What is the Meaning of “Research-Based”?
Home canning has changed greatly in the 170 years since it was introduced as a way to preserve foods. Scientists have found ways to produce safer, higher quality products. Too many times people don’t understand there are risks when processing food at home. Those risks include botulism poisoning, which can lead to illness and even death.
The development of a canning recipe is an extensive process. It involves repeating the entire preparation and canning process 15-30 times to obtain accurate heat penetration data. Then, microorganisms are put into the jars before processing to make sure the processing time is sufficient to destroy them. This research must take place in a laboratory with equipment for testing heat penetration and microbiology. This is why processing times cannot be made up! It’s also why a sealed jar does not mean it’s a safe jar.
I have heard a lot of home canners dismiss the USDA as if it is some governmental agency who only tells us certain canning practices are unsafe so we can’t do it and that is simply not true. The CDC reports:
In the United States, an average of 145 cases are reported each year. Of these, approximately 15% are food borne, 65% are infant botulism, and 20% are wound. Adult intestinal colonization and iatrogenic botulism also occur, but rarely. Outbreaks of food borne botulism involving two or more persons occur most years and are usually caused by home-canned foods.
Printable Download: Botulism Manual, please refer to page 7.
According to the manual, prior to 1950, there wasn’t wide-spread access to ventilators so people died if they contracted the poison before the anti toxin could be administered. After the 1950’s, people could go to the hospital and be put on a ventilator immediately giving them time to administer the anti toxin which decreased the number of deaths dramatically. In a SHTF world or long term emergency such as Hurricane Katrina/Sandy, there may not be access to medical institutions like there are now, so people will either die or live with the severe effects of the poisoning which include; muscle paralysis, double or blurred vision, dry mouth, droopy eyelids, slurred speech, difficulty swallowing and muscle weakness.
More Stories on botulism related deaths in the last 45 years: