Tomatoes: Canning safely at home

Safely can tomatoes at home to savor all winter.

It is tomato time in gardens and markets all around the state. As tomatoes continue to ripen and you begin to think about preserving them for winter, take some time to investigate the recommendations for safe tomato home canning.

One critical aspect to follow when canning tomatoes at home is acidifying them during the canning process. The acidity of tomatoes is considered borderline between high and low acid foods. So to ensure their safety after being preserved, they must be acidified as part of the preservation process. The acidification process is quite simple. To acidify whole, crushed or juiced tomatoes, add two tablespoons of bottled lemon juice or 1/2 teaspoon of citric acid per quart of tomatoes. For pints, use one tablespoon bottled lemon juice or 1/4 teaspoon citric acid. The lemon juice can be added direct to the jars before filling with the tomato product or it can be added after filling. Just be sure to add the lemon juice to each jar and to follow the recommended amounts precisely. Bottled lemon juice must be used, not fresh squeezed. If desired, sugar may be added to offset an acid taste, but the acid cannot be decreased to taste.

Michigan State University Extension reminds home food preservers to always use current, research based recipes when canning tomatoes, as well as any other produce or food items. Recommendations and preservation processes have changed through the years and it is critical to use current methods in order to have a safely preserved product for you to consume. Resources that are recommended include MSU Extension Michigan Fresh, National Center for Home Food Preservation, So Easy to Preserve book, Ball Blue Book (newer than 2000) and the United States Department of Agriculture Guide to Complete Home Canning.

Tomatoes can be canned using a raw or hot pack and using either the boiling water bath canner or pressure canner. Be sure to follow the current, research based recipe exactly as it relates to the type of pack and processing times for the canner type you choose to use.

Acidifying tomatoes when recommended and using current food preservation recipes will give you the confidence in knowing you have safe tomatoes to enjoy through the cold, winter months.