How To Can Tomatoes
By: Amy Jeanroy
Published: July 23, 2014

It's the prime garden season that every vegetable gardener waits for. It's tomato time! Once you have eaten your fill of these delicious fruits, it's time to can them for winter use. 
Canning and preserving is not just for your grandmother's era. It's regained popularity in the last few years, and we couldn't be happier. Tomatoes are a great starter for the beginning canner, because they are very easy to grow in the garden, easy to find in bulk at the farmer's market, and are simple to preserve. 
Tomatoes are canned using a water bath canner. This means that they are a high acid food, and do not require a pressure canner in order to be safely stored in jars. For the beginner, this means that the equipment needed to preserve tomatoes is much less expensive and seem much less of a hazard. Truthfully, pressure canners are safe as well, but that is for another post. 
To can tomatoes, use only ripe, not overripe fruits with little to no blemishes. For instance, if you scraped your tomato that day while unloading it from the car, you can safely use it. If it has a soft spot that needs to be cut out, it is best to chop it up for sauce instead. Damage that is under the skin(also known as decay), could introduce dangerous bacteria into your entire batch of tomatoes and it's just not a good idea. 
Some canning experts now recommend adding a bit of acid to each canning jar of tomatoes, because they believe that modern tomatoes are less acidic than the heirloom varieties. Whether this is true or not, it can't hurt and there is not taste difference. 
Home Canned Tomatoes
From Amy Jeanroy
 
20 pounds ripe red or yellow tomatoes
6 teaspoons coarse salt - (to 8)
12 teaspoons white wine vinegar or lemon juice
 
Preparation
 
Wash 8 quart jars, lids and rubber seals in hot soapy water and rinse. Place the jars and lids in boiling water for 30 seconds to sterilize them. Wash a large canner and lid and dry.
 
Peel and core the tomatoes and cut into halves or quarters.
 
For the Raw Pack method: Pack the raw tomatoes into canning jars to 1/2-inch from the top. Add 1 teaspoon salt and 2 teaspoons white wine vinegar or lemon juice to each quart of tomatoes.
 
For the Hot Pack method: Bring the raw tomatoes to a boil in a stainless steel pot. Then pack into jars to 1/2-inch from top. Add 1 teaspoon salt and 2 teaspoons white wine vinegar or lemon juice to each quart. Be sure the tomatoes are covered with their juice.
 
For either method (raw or hot-pack) be sure to wipe the necks and tops of each jar, fit with a rubber seal and lid, and seal. Fill the canner (it should be deep enough that the level of the water will be 3 to 4 inches above the tops of the sealed jars) two-thirds full with water. Place a rack inside the canner so the jars won't touch one another or the sides of the canner. Bring to a boil.
 
Place the jars in the rack and process raw-pack tomatoes for 50 minutes, hot-pack tomatoes for 45 minutes. Immediately remove the jars from the boiling water and let sit several inches apart on a cooling rack or kitchen towel, away from drafts until cool.
 
After the jars have cooled, check the seals to see that the top resists the pressure of your finger. If there is some give, chances are high that it is not properly sealed. In that case, either eat the tomatoes immediately or transfer to another sterilized jar and process again. Label the jars and store in a dry, dark place.
 
This recipe yields 6 to 8 quarts.