Canning food is the act of preserving food by means of processing it and storing it in a sealed, airtight container. This could be a metal can, glass jar or plastic pouch so long as it does not let air in or out. So the first thing to really understand about canning is that it’s not just for cans.
Originally developed for military purposes in the French armies of Napoleon Bonaparte, canning was conceived as a means to ease the logistics of feeding masses of troops with preserved, transportable food. While early attempts proved costly in time and expensive to produce (making canned goods rare), modern canning techniques have made canned goods inexpensive, safe and abundant.
Being one of several ways to preserve various foods, canning is effective in preserving fruits, vegetables dairy products and meats. Food can be canned in raw and semi-cooked states, but one way or another it needs to be sterile (free from bacteria or any other microorganisms). What goes into the can will stay in the can, and if that includes bacteria, you are probably not going to want to consume what comes out when you unseal it. If you cook food in an already sealed can or jar, it will not begin to spoil until you open it (so long as it is cooked in temperatures exceeding the tolerance of microorganisms). Without microbes or contaminating air in the sealed container, the process known as spoiling will not occur, and organic food will not rot or decompose.
Canning is different than pickling, which requires anaerobic fermentation in brine or immersion in vinegar. As a chemical process, pickling does not require food to be sterile before being sealed off since the acidity of the medium will kill off most bacteria and contaminants.
The purpose of preserving food is to save it and its nutritional value to be consumed at a later date, usually when you no longer have access to the food in its fresh form anymore. This can relate to harvest cycles or preparation for long-term footage shortages and expeditions.
You should can what you have a lot of, and what you like to eat. If you are canning for commercial purposes, you have likely had the plan in mind for a while and accumulated enough food to process in order to sell or trade. If you are canning for personal means, just make sure you are preserving your food for the right reasons; so that you can survive on it (or enjoy it) later, when it is no longer abundant. There is no point in preserving food that you won’t use, and you won’t be able to can food that you don’t have enough of.
Rather, can foods that you have too much of, which you will not be able to finish consuming while still fresh. If you are planning a garden or farm for yourself, consider that you can preserve much of your produce with canning. If you are looking to use a large plot to grow an abundance of a certain fruit or vegetable, make sure it is something you are comfortable with canning and using in the future. Only can produce that is in good, fresh condition and not starting to spoil.
If you end up with a particularly bountiful harvest of a particular fruit, don’t let it go to waste, can it.
Canning can extend the shelf-life of food from anywhere between one and five years, though canned food has been consumed after as long as decades or even a century. Note that both wet and dry food can be canned, and that dried, canned food will often last the longest.
If you are just starting with canning, don’t feel obligated to can enough food to feed an army. Can as much food as you feel comfortable with.
Different foods may require different recipes for most effective preservation; berries may be best preserved in a jam, and carrots might preserve best cooked. There is a lot of literature available with canning recipes from simple vegetables to full turkey dinners. Be sure to have a recipe in mind before you go about canning, and if you are growing food for preservation, make sure you have tracked down an agreeable recipe before committing the time and resources that you will need to. We have a variety of canning recipe books available right here.
Most fruit and vegetable canning recipes require a mixture of syrup, oil or brine for the produce to be immersed in for preservation. Syrup is a mixture of water and sugar while brine is a mixture of water and salt. Additionally, recipes may require the food to be prepared in certain ways before adding it to cans or jars.
Many recipes will require you to heat or pressurize the contents of food being canned at a particular temperature for a specific amount of time in order to sterilize the food, or sometimes to partially (or fully) cook it. This could require a commercial water bath canner or a pressure canner; follow the directions stated in the recipe you have chosen to follow. Canning recipes are everything when it comes to the process. After a couple hundred years of canning, take it from generations of experts and don’t spend your life trying to find new canning recipes if you don’t have to (or want to).
In a pinch, you can simply use a pot of boiling water instead of a purpose-built water bath canner, or a pressure cooker instead of a pressure canner.
Again, one of the biggest things to consider when canning is sterilization. Sterilize your canning containers with commercial sterilizers or by boiling them for 10 minutes, and sterilize all of the tools you intend to use.
Commercially, you can buy canning machines for glass jars and metal cans in a variety of sizes for a variety of purposes from personal to industrial. You can easily purchase small canning kits for home use, or even just jars (and lids) that have been developed specifically for canning.
When your canning process is complete, label and date your preserved foods. If you can, try to eat them within a few years and continue to can new food for use beyond that. If you are able to continue producing food to store, start eating the old stuff. If you are no longer able to produce food, then it would be a good thing to have canned your excess edibles, wouldn’t it?