In our post-pandemic world, more and more people are opting to learn about ways to be more sustainable in their own homes. The threat of food shortages and ever-increasing prices at the grocery store are leading many families to learn about producing and preserving their own food.
Smoking and drying are great options for preserving certain foods. Even freezing allows you to store fresh food for an extended period without necessarily having to cook what you’re saving, raw meat, for example. But freezing requires you always to have electricity to keep your freezer cold. Depending on where you live, one bad or extended power outage could result in you losing much of your food stock. While smoked or dried foods have a decent shelf life, it’s not quite as long as what you could achieve with canning.
A Brief History
Canning has been around since the late 1700s when Napoleon Bonaparte posted a reward for anyone that could come up with a reliable means to preserve food for his notably successful armies. Nicolas Appert discovered the method that laid the foundation for how canning is done still today. (1)
In the late 1850s, the first reusable jar was made, featuring a screw-on lid, and the technique for canning was further perfected in 1915 when the two-part canning lid was invented by Alexander H. Kerr. (1)
How Canning Works
Essentially, food spoilage is caused by microorganisms, and/or the food is broken down by its own enzymes. Canning eliminates both factors through the process of heating the food to high enough temperatures to destroy the hazardous microorganisms and break down the enzymes that would cause spoilage. Heating the filled canning jars and then allowing them to cool, respectively forces air from the jars and then creates a vacuum seal, preventing the air from returning and reintroducing microorganisms. (2)
Three Main Canning Methods – Pressure, Water Bath, and Atmospheric Steam
Pressure canning works with a much higher temperature, around 240 degrees Fahrenheit. This high temperature, coupled with the cooking time and pressure, results in much more thorough extermination of food-borne bacteria and a tighter vacuum seal. Water bath canning is a lower-temperature process but is still effective at killing spoilage-causing mold, yeast, and enzymes. (3)
Atmospheric steam canning wasn’t a widely trusted method until the University of Wisconsin published research that proved it was effective, but it’s strictly for use with highly acidic foods, with a pH of 4.6 or lower. (4)
The technique you use will depend on the type of food you’re wanting to preserve. High-acid foods such as fruits and fruit juices, jams and jellies, pickles, tomatoes, chutneys, condiments, and vinegar, are better suited to water bath canning or steam canning (again, if the pH is low enough). Low-acid foods such as meat, poultry, seafood, vegetables, and chili are better suited to the pressure canning method. (3)
Find Canning Recipes & Stick to Them
There are countless canning recipes to choose from. Whether you’re using your Great Grandma’s jam recipe or just picked up a canning cookbook from your local bookstore, make sure you follow the recipe down to the letter. This is to ensure the bacteria and enzymes in the food are destroyed properly so your precious food stores don’t go bad without your knowledge. The recipe is always specific to the method of canning, so make sure you make note of that as you prepare for your first canning session.
Shelf Life of Home Canned Foods
While store-bought canned foods usually have an expiration date set 2-5 years from the manufacturing date, unopened food canned at home has a general shelf life of one year or two at the max. Low-acid foods typically have a longer shelf life than high-acid foods. (5)
As you probably do with regular leftovers in your fridge, it’s best to use your home-canned food on a first-in, first-out basis. In other words, eat the oldest first. As you add newly sealed jars to your stock shelf, put the newest in the back so it’s easier to pull the older jars right from the front. Also, make sure you’re properly labeling your jars with the canning date.
Acquire Your Equipment
If you’re new to canning, it might be a good idea to borrow a set of equipment from someone you know. This will give you a chance to test out different methods and recipes to find what you like before investing in your own supplies.
At the minimum, you will need canning jars with two-part rubber sealing lids, a jar lifter, a wide-mouth funnel, measuring cups, a ladle, a canning vessel for your chosen method, and a recipe. Several other accessories can make the process easier for certain foods, such as a Victorio strainer or food mill for removing skins and seeds in tomato juice or applesauce, but those first few items are the basics. (6)
A deep stock pot is perfect for a boiling water bath method, just make sure it is deep enough to hold your jars which will need to be totally submerged in water while set on a round rack within the pot. (1) A pressure canner is obviously required for the pressure method. If you’re using the steam method, there are pots specifically designed for this method. (2)
Hopefully, you now have a basic understanding of how canning works and what method you might want to employ to preserve the foods that you grow in your garden or even your favorites from the supermarket.
Preserving your own food is a step in the right direction for self-sufficiency. If you have a garden that consistently produces more than you can eat or even give away before it spoils, learning to can your own food is a great addition to your skill set. In these trying times, being that much more sustainable could only be a good thing.
Canning Supply Checklist
- Canning jars with a two-part lid
- Canning vessel, such as a stock pot or pressure canner
- Jar lifter
- Wide-mouth funnel
- Measuring cups
- Canning recipe
- Other optional accessories for your chosen recipe, such as a strainer or food mill