Canning Tomatoes

by Susan Lott

If you've never tried canning before, tomatoes are a good first canning project. Tomatoes don't go brown when exposed to air like peaches do, so you can take your time to make sure everything is just right between steps without damaging the product. They're messy, but definitely worth the cleanup.

Tomatoes are best when they come from your own garden. The the flavor is better, often they are more acidic, and they are picked vine-ripe for maximum flavor and nutrition. If you can't get any local garden-grown tomatoes, you can use the kind from the market, but they just won't taste as good because they're picked green and ripened chemically with ethylene. Yuck.

Step-By-Step Instructions

1. Prepare Tomatoes. Wash the tomatoes. Cut out the stem and any dark spots or blemishes. Place them in a pan of simmering, but not boiling water for 1-2 minutes to loosen the skins. Turn them over to make sure the entire surface gets a turn under the water. When the skins split, take them out and place them in a large bowl to cool. The skins will now easily peel away.

2. Peel Tomatoes. Peel the tomatoes over the large bowl so that you capture all the juice. Reserve the juice for later. Some people use a bowl of ice water for cooling, but I don't because I want to keep the juice undiluted.

3. Pack Jars. Cut the peeled tomatoes into quarters, and pack into quart jars. Don't pack the jars too full or they won't seal. You can use pint jars if you want to.

4. Add Preserving Ingredients. Add 1 tsp salt per quart. See the note below on acidification if you choose to add an acid booster. I usually add ¼ tsp citric acid only if I'm not satisfied with the tartness of whatever I'm using. Strain the juice that you reserved in the peeling bowl. Pour an equal amount of juice into each jar. Finish filling the jars with water if needed, to within ½ inch or so of the top of the jar.

5. Cap Jars. Next, wipe off the top of the jars with a clean damp cloth. This will ensure that the sealing surface is clean and free of particles that would break the seal. Bring a small saucepan of water to a very hot temperature, but not boiling. Put your lids in the water for about 30 seconds. Place the lids on your jars and screw the rings on finger-tight. Here is a video to show how easy it is to cap your jars, for those who haven't done it before.

6. Process. Fill your big canner pot about 1/3 full of water. The temperature of the water should be as close as possible to the temperature of the jars. Place the jars in the rack and make sure the water level is such to barely cover the jars. Bring the water to boil and leave the heat on high. Time your processing from when the water starts to boil. Process for 45 minutes.

7. Let the Jars Cool. When the time is up, lift the rack out of the water. You may hear some caps pop at this point if the air temperature is cool enough in the room. The pop is the sound of the cap sealing. Using a jar lifter or a dry hotpad, lift each jar out and set it on a heat tolerant surface to cool. Sometimes, but not always, jars will pop as they seal. Let the jars cool thoroughly and mark the caps with the year so you always know how old the jars are. A good jar seal test can be found here.

NOTE - Don't move the jars while they are cooling and don't put them away until they've cooled all day or overnight. I put them away too warm once and they all came unsealed. If any jars did not seal, leave them unopened and they will keep well in the fridge for a few weeks.

Troubleshooting

Jars did not seal- The most common problem that could have been caused by any of the following: lids were defective, lids were too old, lids were in the hot water for too long before capping, jar surface was not wiped gunk-free, jars were placed too close together while they cooled.

Acidification

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