What is Canning?

by Susan Grey on May 17, 2019
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Canning refers to preserving food content by processing and sealing it in airtight containers (cans). Canning provides up to 5 years of shelf life and can be extended to even 30 years depending on the circumstances as well as the type of food being preserved.
Nicolas Appert invented canning in 1809 as a response to the French government call for innovation in army food preservation techniques.
50 years later his work was perfected by Louis Pasteur who introduced pasteurization. This technique involved heating the food content to kill the microorganisms in it followed by sealing in airtight cans to keep other microorganisms from entering the jar.

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Modern Canning Process

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The process is relatively similar between industrial canneries and the steps people take to can food at home. The only difference is that the industrial process is much stricter and more automated. Generally, canning follows the following steps:
1. Preparing the Food to be Canned
Food preparation is unique across different foods; therefore, the process is guided by the recipe of choice. Fruits are peeled in this stage while vegetables and meats are cut into appropriate sizes. Pits, stems and other inedible parts of the food such as cores and bones are also removed.
In the industrial process, the canneries utilize blanching process to prepare and cook the food. The process involves pouring boiling water on vegetables or fruits to loosen the outer skin.
2. Preparation of Canning Liquid
Majority of fruits and vegetables are canned in syrup which is prepared by mixing sugar with water or juice. Cooked foods, on the other hand, are canned with brine which is a mixture of salt and water.
If you intend to pickle the food, then a basic mixture is required. Such a combination should be prepared by mixing vinegar, salt, and water and bringing the mixture to boil. You can also add garlic to flavor.
3. Sterilizing the Cans
The jars and cans that you intend to use should be wholly sterilized to eliminate any bacteria which would otherwise make the food to go bad. This is achieved by boiling them in water for about 10 minutes. Allow additional time if you are at high altitude as the water boils under lower temperatures in such areas.
4. Filling the Jars
This process is relatively simple, gently add the prepared food into the jars and top off with the canning fluid. You can also add preservatives such as ascorbic acid and lemon juice during this phase.
5. Sealing
Wipe off any food particles that may have been spilled on the can before continuing. Depending on your container you can either use softened seal or tin lid. Either way, the seal should be airtight enough to prevent air or bacteria from entering the can.
This process will differ slightly depending on whether you are using specialized canning equipment such as water bath canners or a pressure canner. The key to successful canning with such equipment is following the manufacturer’s guidelines.

Why Can Food?

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  • Preserve Seasonal Food Varieties

    While your kitchen garden is more than capable of providing an all-year-round supply of vegetables, some crops only produce annually such as peaches and apples. Others such as tomatoes will only grow during the summer season when the weather conditions are conducive enough.

    It, therefore, makes much more sense to preserve such seasonal food varieties and use the reserves when it is not fresh readily available. Canning is not only easier but is also much cheaper compared to other preservation techniques. Your canned reserves are also bound to retain the taste and nutritional content unlike with freezing.
     
  • Saving Up Excess Produce

    After a bumper harvest, you can either sell the surplus produce to your neighbors or at the local farmers market. Such options might still not completely take care of all that zucchini or apricots that you have managed to harvest. Instead of letting this produce go to waste you can preserve it for later sales or consumption.

    Canning provides a cheap alternative to save up on your excess produce without incurring any storage costs as all canned produce can be safely stored in your pantry for months thus eliminating food wastage.
  • Promote Healthy Eating

    One of the main reasons most of us adopt homegrown food is so that we can eat healthy food and by healthy, I mean GMO-free and BPA-free products. After you have grown your GMO-free food, it then makes perfect sense to store some of the produce for future consumption until the next production season kicks in.

    Bisphenol A. (BPA) is a chemical that’s used in the manufacturing of plastics and resins that are used to store food and beverages. BPA can seep into such food or drinks from the containers during storage leading to adverse effects on brain and prostate gland development in infants. It, therefore, makes much sense to avoid such storage solutions by relying on canned food instead of plastic-stored food (link).
  • Quality and Taste

    When it comes to food quality and taste nothing beats a home-cooked meal. Preserving such natural taste for future consumption will defiantly come in handy. Canning offers a healthy and long-lasting way to stock up on tastier products in your pantry.

    Other products such as tomatoes produce more lycopene when canned thus giving them a richer taste and color as opposed to fresh produce. While other products such as vegetables will acquire distinctive taste from the canning acids making them a fun option to tweak your recipes as you experiment with new flavor combinations.
  • Sentimental Value

    Some canning recipes have been handed down from generation to generation; these not only hold sentimental value within a family but also remind us of a simpler time. These unique recipes make for the perfect home-made gifts as well as conversation pieces when entertaining guests at your home.
    Canning provides a rather strong connection to our past, our culture as well as heritage and it's only fair that we continue practicing this age-old food preservation technique in the hope that the future generations will keep it going.
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5 Foods That Can Be Canned

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1. Fruits
Fruits usually go bad if they are not stored under the right condition, their shelf life can only be a maximum of a few weeks before they are over-ripe and start rotting. However, with canning, you can preserve your fruits until the next annual harvest thus providing ample supply during the scarce months.
Some of the fruits that can be canned include apples and apple products such as crabapple jellies, pear-apple, and applesauce. Apricots can also be canned either in whole or as jam, cherries, grapes and grape juice, pears, rhubarb, peaches, and plums. Some of these fruits may require additional preparation steps during canning so consult reliable internet guides before embarking on the process if you are a first timer (link).
2. Tomatoes and Tomato Products
Tomatoes get a whole category on their own due to the diversity involved in their preservation techniques and because we tend to treat them as vegetables rather than fruits. Depending on your canning recipe you will either end up with tomato sauces, salsas, relishes, ketchup or whole tomato fruits.
Either way, your canned tomatoes not only improve in taste and color during canning but will also last way longer than any other preservation technique (link). 
3. Vegetables
Vegetables tend to lose their moisture content a few days after being harvested; this is then proceeded by either rotting or drying up making them inedible in no time. For this reason, its recommended to preserve them right away after harvest, while you can freeze them most will lose their taste and turn soggy during thawing. All this can be avoided by canning your fresh vegetables.
Some of the best vegetables to can include snap beans, sweet corn, peppers, cubed pumpkin and winter squash, asparagus, potatoes, sweet potatoes, okra, carrots, and beets. It's important to note that most vegetables are best canned using a pressure canner.
Interested in learning more about how to can mushrooms? Check out our post here (link).
4. Meat, Poultry and Sea Food
While raw meat, poultry, and seafood products are best preserved by refrigeration the same cannot be said of cooked meat products. Such dishes are best preserved by canning, but there’s a catch; meats MUST be canned in a pressure cooker as there’s no safe way to perform the same using a boiling water canner.
Either roasting, browning or stewing can precook such products. The cubed pieces are then added to a jar which is then topped off with boiling broth, and a 1-inch headspace is left before the jars are tightly sealed (link).
5. Pickles and Fermented Products
Relishes and pickles are some of the most popular condiments served with meals. Cucumbers and cabbages are the main vegetables that are pickled. These are easy to prepare and are loaded up with vitamins. Sauerkraut represents the majority portion of fermented pickles giving them a characteristic lactic acid flavor.
Pickling relies on maintaining a high acidity level to prevent the growth of dangerous bacteria such as botulinum bacteria. For this reason, its never a good idea to interfere with the vinegar, water or food proportions in a recipe. Also, avoid using vinegar with unknown acidity level as this might be below the minimum necessary level of acidity to keep the food fresh.

 

 

Interested in learning more about fermenting & preserving?
Check out these articles:
How Long Does Sauerkraut Last?
How Long Does Kimchi Last?
What Does Sauerkraut Taste Like?
What Does Kimchi Taste Like?
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