There’s a whole smorgasbord of food you can easily store with a pressure canner. Not everything, however, as a home-canned preserve, retains its ‘safe to eat’ status. Fortunately for preppers, the list of what can be protected much outweighs the list of what is not. Also, it is generally possible to preserve foods that can not be canned in other ways, so there are still choices to store your homegrown harvest or even shop-bought haul.
Although you can safely use a boiling water-bath method to ‘can’ many foods, some bacteria can survive at normal boiling-water temperatures, but not at the 240-degree heat that can be reached by a home pressure canner.
The key to what is safe to do in a water bath and what is not is largely linked to its acidity, and where the pH scale of a food falls. Low-acid foods with a pH of 4.6 or higher are typically only suitable for processing in a canner, while foods with a lower pH are considered suitable for canning water baths.
So What’s In and What’s Out?
But there are certain ingredients that can not be home-canned safely at all. In the shop, especially at Christmas, herbs or garlic in oil may be a popular sight, but can not be safely replicated at home. Pumpkin (or any other kind of squash) in butter or puree form is another seasonal favorite best left to the commercial canning industry.
Cubed pumpkin, on the other hand, is nice to be able to do. And why does the disparity exist? In simple terms, it’s a matter of how the pumpkin’s texture is altered and how heat conducts the density. Domestic canners can’t adequately penetrate the thick material to make it safe to consume.
A Question of Density
For other foods, the question of density still applies. Bananas, avocados, fatty meats like liver and pate are all on the food list to stay away from your canner.
While cream soups, tinned pasta, oats, biscuits and milk products could groan in the shelves in your local supermarket; again, these types of food should be left to industrial canning processes as they can not be safely replicated at home.
Additionally, some vegetables, such as broccoli and cauliflower are unsuited to the high temperatures needed to can safely and will end up as little more than a slurry.
Canned Recipe Foods
Recipe foods are fabulously easy to make and enjoy new, but unsuitable for home canning, including basic foods such as pesto or peanut butter. But what if you have a favorite recipe that you think will be perfect canned, and you know it separately; all the ingredients are ‘safe-to-can’?
There is a chance you do not need to take without access to a competent testing laboratory and tracking test batches to assess safe cooking times and temperatures for an amalgam product with increased density and viscosity.
The other primary form of food to avoid is dairy. If you try to can it, the to-die-for salted caramel sauce might end up having just that effect (or at least sound like it!). In fact, a recipe like this would have double the risk of rancid butter or cream, and the viscous density of the food would be resistant to thorough and even processing.
The good news is that nearly everything can be preserved somehow. Vegetables and eggs can be pickled. Pumpkin purée can be made into leathers. Even butter can be preserved in a butter bell for up to one month.
Is Grandma’s Way Always Best?
A controversial problem is always what can be canned and what can’t. Everyone has their own tried-and-trusted tactics, and for decades, there are still tales about how things have been handled and no one has ever gotten ill. But it changes stuff. Pesticides and herbicides are used even more; chemicals that can tweak the natural acidity of production can compromise the soil quality, and improved testing and industrial canning techniques have illustrated the risks of getting it wrong, big and small.
As in many things, there is a position for information of all sorts. An excellent formula for success is always a blend of inherited wisdom, up-to-date advice and a good dose of common sense!