Food Preservation: Basics of Canning

Some of my favorite memories as a child are helping my grandma do her canning. Another is eating the foods that my family had canned. A lot of folks in my family canned while I was growing up. Mom, both my grandmas, great grandma, some of my aunts, even my great uncle!

The first order of business is to gather together your equipment, your food to be canned, and select your method of processing. In this case I am canning marinara sauce, so I will be using my pressure canner for processing. Once you have gathered your equipment, you should sterilize it either with boiling water or in your dishwasher, if your dishwasher is equipped to do so. It is important to time everything out so that your food and jars are hot at the same time that the water in your canner is boiling. It is also important to keep your  pressure canner's user manual handy. It will provide you not only with recipes and ideas, but important information regarding head space, canning methods, proper pressure, and proper processing times for canning your food.

While you start the water boiling, you should start filling your hot jars with hot food using your canning funnel.










Using your head space tool, measure how much head space you have and adjust accordingly. This recipe calls for 1/2" of head space. Your head space tool can also be used to release air bubbles trapped in the jar before processing. Foods such as vegetables, pickles and relish may have trapped air bubbles that need to be released. Just slide the rounded end of the tool down the edges of the jar and watch the bubbles bloop to the top.













Once your jars are full and have the proper head space, the rims of the jars need to be wiped clean with a damp dishcloth or paper towel. This will ensure that the adhesive can stick to the edge of the jar, without any food getting in the way.















Follow the manufacturer's instructions on how to sterilize your lids. The typical method for this is to submerge them in simmering water. Remove them from the simmering water with your lid lifter and place them on the jars, taking care to avoid contamination.

Once your lids are all in place, you should gather together your canning rings.



















Twist on your canning rings and tighten until "finger-tight." You don't want to crank them down too hard, or your jars may explode, or too loosely, allowing the contents to boil over and out of the jar. It may take a few batches to get it right, so don't get discouraged!













Lower your hot and freshly lidded jars into the boiling water of your canner. Be sure to use your canning tongs to avoid your fingertips being burned by the hot jar, the steam, or the boiling water.

















If you notice that the water level has dropped a bit, add enough hot tap water to bring it back up to the correct level. Bring the water back to a boil before moving on.









Once your lid is on and pressure is achieved, it will be indicated by this little button that pops up. This button also indicates that your canner is locked and the lid cannot be taken off until the pressure has dropped off. When your button pops up and there is a solid jet of steam coming from the pressure stem, set a timer for 10 minutes. When your 10 minutes is up, add your weight and watch it rock!




This first video shows what the movement of your weight will look like if the temperature is too high. See how it is spinning more than rocking, and how erratic its movements are?

Lower the temperature on your stove and it will slow down and become more rhythmic. You want a slow, steady, back and forth motion.

After your food has processed for the amount of time indicated in your pressure canner's user manual, turn off the heat and carefully move your canner away from the heat. Now, leave it alone and let it cool! Don't get impatient and try to hasten its cooling. This could not only affect the quality and safety of the food inside, but you are running the risk of injuring yourself as well. Just be patient and let it cool! Remove your jars with canning tongs and set them on a dishtowel on your countertop once the canner is cool enough to open.


Once you have put your hot jars onto their dishtowel home, leave them be. They shouldn't be bumped, jostled or moved again until they are completely cool. Listen for the pop as they seal in the video below.

Now it's time to enjoy your freshly canned foods! I had some leftover marinara sauce that wouldn't fit in my jars, so I made a "poor man's" Chicken Parmesan out of a chicken patty, complete with a hotdog bun garlic bread. Yum!

Food Preservation: Canning Equipment

Described below are the basic pieces of equipment you will need to begin canning. In later posts I will explain exactly how to use them all, but I thought that I ought to do an introduction and explanation of the things you will need to acquire in order to get started, before I make a post on how to do the actual canning.

Canning Jars - Modern canning jars come in a wide range of sizes ranging from 2 oz to a half gallon. There are two different mouth sizes, which are called regular mouth and wide mouth. They are self-sealing, which means that the lids will adhere themselves to the jars after processing for a set period of time. Processing can be done either in a boiling water bath, or inside a pressure canner, depending upon what foods you are canning.













Canning Rings - Canning rings are screw-on rings designed to hold the lid in place while processing. They hold the lid firmly in place until a vacuum is achieved and the lid adheres itself to the jar. After the jars are sealed, the ring may be removed for storage.














Canning Lids - Canning lids have a heat-activated adhesive around the edge which allows them to adhere to the edge of the jar mouth after processing. Once the jars are removed from the heat, after processing, a vacuum is formed which seats the lid onto the jar. Once the jar has cooled, a tight seal is formed and you can remove your ring for storage. You should be able to pick up your jar by the lid without it falling off, that is how strongly it adheres.



Pressure Canner - A pressure canner is a device used to can foods. It works by using the pressure to increase the temperature at which the foods are being processed. This heat kills bacteria better than the boiling water method, and also cuts processing times much shorter.








At the top of the lid there is a pressure escape stem which a weight fits over. This is how you control how many pounds of pressure are inside the vessel.









The weight comes apart and each of the pieces represents 5 pounds of pressure. Add just the base and it's 5 pounds of pressure. Add to that a ring and it is 10 pounds. The completed weight with both rings is 15 pounds of pressure.








The lid of the canner locks onto the pot by twisting after you have lined up the indicator arrows and dropped the lid into place.










Inside the lid you can see the gasket which seals in the steam and, therefore, the pressure. The nub on the lid toward the top of the photo is a pressure indicator button. Once the pressure inside reaches a certain level, a button on the top of the lid pops up. You should never attempt to open a canner while it is at pressure.






Inside the pot is a rack on which your canning jars rest. The rack keeps the jars away from the direct heat of the burner, and ensures that the boiling water at the bottom of the canner doesn't upset the jars while they are processing.








Always keep the user manual for your pressure canner on hand, and review it each time you use your canner. Working with pressure vessels can be dangerous and it never hurts to double check that you are doing everything right. There are instructions for the canner, instructions for canning (i.e. processing times, head space allowances, etc.) and even some good canning and pressure cooking recipes in here.












Canning Pot & Rack - Although pressure canning is viewed as the safest method of canning, as far as killing bacteria and avoiding food-born illness, boiling water canning is safe for certain foods and under certain conditions. If you wish you can purchase a large pot, like the one pictured at right, and a canning rack that fits inside. Sorry I don't have a picture of the rack, but I typically just use my pressure canner for my boiling water processing as well. Just don't lock the lid on, and it works fine!


Lid Lifter - A lid lifter is basically just a magnet on a handle. It is used to lift canning lids out of the hot water, and place them onto jars without your fingers contaminating the lids.









Canning Tongs - Canning tongs are used to lift and lower jars into and out of boiling water. Canning jars are very hot, even before they have been processed, so please always use your canning tongs to avoid injury.








Head Space Tool - The head space tool pulls double duty. The stair-stepped end is used to measure head space. (The amount of space between the food being canned and the rim of the jar.) The flat handle can be used to coax air bubbles out of the food before you process. Both are important in achieving the correct seal, no leakage, no explosions, and the correct shelf life.





Canning Funnel - A canning funnel is a specially designed funnel made to fit canning jars. Its opening is wide enough to allow the foods being canned to pass through easily. Canning without a funnel would be a huge mess. I think I would end up with more on the counter top than in the jars.