Don’t want to throw out extra tomatoes? Making salsa is a great way to preserve them! But it is important to follow the guidelines for keeping your home-canned salsa safe.

Only use tested recipes when making home-canned salsa. A tested recipe assures there is enough acidity for safe processing in a boiling water bath. These resources offer tested recipes and tips for canning tomato products safely:

• MU Extension’s guide sheet How to Can Fresh Tomato Products has a tested recipe for salsa.
• The National Center for Home Food Preservation website offers recipes for traditional salsas as well as more unusual combinations, like Mango Salsa, Peach Apple Salsa, Spicy Cranberry Salsa, Spicy Jicama Relish and Tomatillo Green Salsa. These recipes can be found at https://nchfp.uga.edu/how/can_salsa.html.

If you are using a family recipe that has not been tested, the recommendation for safe preservation is freezing.

When using a tested recipe, there are some things you can change and some things you cannot change.

Never change the amount of acid in a salsa recipe. Acid in salsas helps to preserve them. It usually comes in the form of lemon juice, lime juice or vinegar. Use only vinegar that has 5 percent acidity and only bottled lemon or lime juice. The acidity in fresh-squeezed lemon or lime juice varies so you can’t trust that the end product would have the needed amount of acidity for safety. It is OK to substitute an equal amount of bottled lemon juice for vinegar in salsa recipes, but it is not OK to substitute vinegar for lemon juice. Substituting vinegar for lemon juice results in less acid and could be unsafe.

The spiciness of salsa can be adjusted by substituting one type of pepper for another, or by adjusting the mix of hot and mild peppers. You should not, however, increase the number of pounds or cups of peppers in the recipe. The same goes for onions — you can substitute red, yellow or white onions for each other, but do not increase the amount. Increasing the amount of peppers or onions can impact the acidity of the product, potentially making it unsafe.

Canned salsas should not be thickened with flour or cornstarch before canning. Thickening makes it harder for the contents to reach the right temperature during processing and impacts safety. If you desire a thicker salsa, just pour off some of the liquid when you serve it or thicken the salsa after you open the jar.

You can find more information and classes on home food preservation at your local University of Missouri Extension Center.