A Basic Canning How-To Guide

Michael Nolan
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As more people begin to grow their own food, it makes sense that there would be a renewed interest in the time-honored tradition of home canning. The process of preserving food at home is not simple or fast, but it need not be as complicated or scary as you might think either. While you should always ensure that you are working with clean, sterile tools to avoid bacteria, the truth is that with a little knowledge, a few basic tools and precautions you can be well on your way to preserving the harvest from your home garden in no time at all – without the fear of poisoning yourself or your family.

Step 1

Before you begin, you should inspect all of your jars thoroughly for cracks, chips, or breaks. Any jars that are not in top condition should not be used as they may allow for air to leak in, and this will foster the growth of bacteria. A visual inspection is enough for the jar itself, but you need to pay specific and careful attention to the rim of the jar. The rim should be completely intact and smooth. If you don’t want to run your finger along the edge to feel for lumps or cracks, use a regular cotton ball. Run it lightly along the entire rim all the way around clockwise, and then counterclockwise. If there are any chips or cracks, the cotton will snag.

Step 2

Fill your stockpot with enough water to cover the jars when they are inside. One easy way to make sure you get the right amount of water is to place the jars inside the pot while you are filling it. Fill each jar with water as well, and let the water run until it is about an inch above the rim.  Place the pot on the stove on high heat and allow it to come to a rolling boil.

Boil the jars for no less than 15 minutes to ensure that they are completely sterilized. Don’t start timing it until the water reaches a full boil. Carefully remove the jars with canning tongs, returning the water to the pot.

Step 3

Wipe new jar lids free of dust and debris and place them in a small saucepan. Ladle in about 2 cups of boiling water from the stockpot. This will serve to remove any residual dust as well as to soften the underside so that it will meet smoothly with the rim of the jar.

Step 4

Even though I am canning a lab-tested tomato-based product that has been cooked, I still need to make sure that there is enough acid in it to protect my marinara from spoiling. For this reason, the USDA Guidelines recommend that you add 2 Tablespoons of lemon juice or 1/2 teaspoon citric acid to each quart jar (half that amount for pint jars) before filling them with sauce.

Next, using a canning funnel, carefully ladle your sauce into the jars. Leave no less than 1/4″ of headspace in each jar, which is approximately where the ring around the top is. If you overfill, use a spoon to remove some of the sauce. Finally, run a butter knife down into each jar to remove any air pockets.

Step 5

When finished, dip the corner of a clean, soft cotton towel into the boiling water and run it along the rim of each jar to remove any remaining sauce. This is yet another step to ensure that your jars are completely sterile, so don’t skip it.

Step 6

Remove the jar lids from the saucepan with a canning magnet (also called a lid wand). Place a lid on each jar and then screw on a ring until it is just finger tight. Do not tighten it any more than that.

Step 7

Using your canning tongs once again, carefully lower your jars into the water bath. Once all jars are in place, ensure that the water level is no less than an inch above the top of the jars. Let the water return to a full rolling boil and set your kitchen timer for 45 minutes.

NOTE: Specific processing time will vary depending on your altitude and what you are canning. Please consult the USDA Complete Guide to Home Canning for the proper processing time for your situation before you begin the canning process.

Step 8

When the required processing time has elapsed, remove the jars to a cooling rack using the canning tongs and allow them to cool.You will soon begin to hear a PING! sound as the jar lids create their vacuum seal. Don’t worry if the jars seal and then release once or twice while they are cooling; this is completely normal. When the jars are cool, they should be sealed. It is a good idea to check your jars again in a day or two to make sure the seal has remained. Never eat anything out of a jar if the seal is broken.

It is very important to note that a water bath process is only to be used when canning foods that are highly acidic.


A tested tomato or marinara sauce (USDA approved recipes and info here)



USDA Complete Guide to Home Canning (PDF file)

Canning Jars & Lids

Canning Funnel (kit)

Canning Tongs (kit)

Large Stockpot



Butter knife or long-handled spoon

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