Home Hot Water Canning: How To Do It

Hello again. In this post, I’m going to talk about prepping your canning jars and lids, as well as walk you through the actual canning process.

For this example I’m going to be processing tomatoes, a high acid food perfect for hot water canning. However, to be on the safe side, an additional acid such as lemon juice (1 tablespoon per pint, 2 tablespoons per quart) or citric acid (¼ teaspoon per pint, ½ teaspoon per quart) should be added prior to canning. This increases the acidity (lowers the Ph) and helps prevent the growth of botulism or other unpleasant organisms.

Examine Your Produce

Before getting started, examine all the tomatoes for blemishes, bruises, or other damage and cut out bad spots if necessary. Any tomatoes that are over-ripe or have even the slightest amount of mold should be excluded from canning. They may still be perfectly fine to use in regular cooking, but the requirements for proper canning are pretty stringent.

Blanching the tomatoes (dipping them in boiling water and removing the skins) can often result in a better product, but is also a lot more work. I’ve canned whole, blanched, diced, and crushed tomatoes; the easiest by far was running them through the food processor and canning the result. However, consider what any recipes call for and choose accordingly. 

You also need to decide between hot pack and raw pack, also called cold pack canning. The difference is simply whether the contents are raw but room temperature (such as fresh or blanched tomatoes) or cooked and still hot (such as stewed tomatoes). Again, personal preference and ultimate use will be deciding factors.

Once the contents and method have been decided, it’s time to move on to the next stage.

Examine Your Equipment

The first equipment check to be made when getting ready to can is to examine the jars, making sure they don’t have any cracks or chips. 

Then, wash the jars in hot water and dish soap. If you have a dishwasher, it may have a sterilize setting.

Next, open a fresh package of lids and wash them as well. It’s important the lids not be boiled, as this can soften and weaken the ring of sealant around the edge, preventing a good, airtight, seal. This is why lids generally cannot be reused for another cycle of canning.

Start Your Engines (Process)

Place the canning pot on the stove top, fill it part way with water, and turn on the heat. Remember, the pot needs to hold enough water to be at least a couple of inches above the top of the jars when boiling. 

If you have a glass-top stove, be cautious; the size and weight of a large canning pot full of water and jars may damage or break the cooktop. Consider using a smaller setup if this is a concern.

Preheat the jars by soaking them inside and out with hot water. Not doing so increases the chance of jars cracking or shattering when plunged into hot water.

Fill the jars using a food funnel, but make sure to leave proper headspace, which is the air gap between the top of the food and the inside of the lid.

For tomatoes, the jars should be filled to no less than half an inch of the top; I prefer leaving closer to an inch of headspace.

If using whole, quartered or diced tomatoes, add water or tomato juice to fill the excess space in the jars. Crushed tomatoes should be fine as is.

Use a plastic or silicone rod to work out any air bubbles in the contents. Wipe the top rim and threads to make sure there’s nothing that would interfere with a good seal.

Place the lids on the jars and screw the rings on, but not too firmly! If the rings are screwed on too tight, air can’t escape during boiling.

Now We’re in Hot Water

Place the jars into a canning rack and lower the rack into the hot (but not yet boiling) water. If necessary, add more hot water until there’s at least an inch or two of water above the level of the lids. Don’t pour the water directly onto the jar tops; try and pour it between the jars instead. 

Put the lid on the pot and turn up the heat. Once the water reaches boiling, start a timer; for sea level to around three thousand feet elevation, pints should be boiled for 40 minutes and quart for 45 minutes. As elevation increases, so does the time, since water boils at a lower temperature at higher elevation. For example, the recommended times for 3,000 to 6,000 feet of elevation is 50 minutes for pints and 55 minutes for quarts.

You can find more information regarding times, elevation, and much more here.

Out of the Water and Onto the Towel

Once the time is up, lift the jar rack out of the pot and, using a jar lifter, move the jars to a towel so they can cool. You should hear a pop from the lids as the jars cool. This is the sound of a good seal.

However, you should check each jar to make sure. Remove the rings and gently push down on the center of the lid. It shouldn’t have much give. If it pops in and out, the jar didn’t seal. Don’t worry, if that happens; it can either be run through again with a new lid, or you can put in the refrigerator and use it in meals. 

Repeat these steps until all the tomatoes are processed.

Storage

Once everything is done and the jars are cool, store them in a cool dark place until needed. Never stack anything on top of a sealed jar! This can cause problems with the seal.

Check on them occasionally to make sure none of the jars have leaks. When opening the jars, examine them carefully before use. If anything seems off, discard them! Botulism can kill in very small amounts.

Thanks for reading. Till next time.