Most tomato-based salsas are a mixture of tomatoes, onions, peppers and spices. To home can in a boiling water bath, you must follow research-tested recipes to assure the proportion of acidic ingredients is high enough for food safety.
Salsa safe canning tips
- Choose only high-quality, disease-free, firm produce for canning. Canning is NOT a way to use overripe or damaged tomatoes, or tomatoes from dead or frost-killed vines because these may cause the home-canned product to spoil and be unsafe to eat.
- Salsa needs added acid to ensure product safety. Tomato varieties and colors can be mixed and matched for salsa but you still need added acid to make sure the product will be safe.
- Researchers at North Dakota State University tested 14 varieties of tomatoes grown at a ND research center. They tested the pH or acidity level of tomatoes and salsa made with lemon juice and salsa made without lemon juice. All 14 varieties of tomatoes tested had a pH above 4.6. All salsa with added bottled lemon juice tested well below a pH of 4.6 needed to prevent botulism. All varieties of salsa without added lemon juice tested above 4.6 and a risk for botulism. This research explains why an acid must be added to tomatoes when home canning them to lower the pH and prevent botulism.
- Don't reduce the amount of lemon or lime juice or tomatoes indicated in the recipe.
- Use dry measuring cups for tomatoes, onions, peppers and liquid measuring cups for bottle lemon or lime juice.
- Chop tomatoes, peppers, onions into ¼ inch pieces.
- Don't add extra peppers, onion or garlic. You can substitute one type of pepper for another or reduce the amount of peppers, onion or garlic.
- Dry spices may be adjusted to personal taste and won't affect safety.
- Don't thicken salsas with cornstarch, flour or other thickeners before canning. Add thickeners after opening the salsa if desired.
- Always store open jars of home-canned salsa in the refrigerator.
Only use a research-tested recipe when canning salsa
- Don't attempt to can a recipe that hasn't been tested for safety, because food spoilage or a foodborne illness may result.
- The National Center for Home Food Preservation Choice salsa recipe lets you choose if want more flavor from peppers or onions.
- Canning recipes for salsa are popular on food blogs and social media sites. The University of Maine researchers evaluated 56 home canning salsa recipes from 43 blogs and found 70% of the recipes did not include USDA food safety home canning standards.
- Direct your online query to search for government and university sites by typing site:.gov or site:.edu. For example: “canning salsa site:.edu”.
- Credible and standardized salsa recipes will instruct you to use pint jars and give processing times for only pint jars. There are no currently research tested guidelines for processing salsa in quart jars. There are no formulas for extending the processing time for a larger jar.
If you use an untested recipe or like to be creative by adding your own amount of ingredients, either freeze your salsa or store it up to one week in the refrigerator and eat it fresh.
What type of tomato works best in home canned salsa?
The type of tomato you use in your salsa will affect the salsa quality.
- Italian plum-style or paste tomatoes, such as Roma, have firmer flesh and produce a thicker salsa.
- Slicing tomatoes produce a thinner, more watery salsa. If you use slicing tomatoes, you can thicken your salsa by adding tomato paste or by draining off some of the liquid after you chop the tomatoes. Never add flour or cornstarch to salsa before canning because an unsafe product may result.
- Choose fresh, firm tomatoes at their peak ripeness. Use tomatoes free of bruises, cracks, disease or insect damage. Soft, overripe or tomatoes with bruises, cracks, blossom end rot, mold, insect damage, or harvested from dead or frost-killed vines can alter the acidity level of the entire batch and make it unsafe. Diseased or bruised produce may harbor pathogens. The process time may not be sufficient to kill extra organisms contained in damaged or diseased produce.
- Dried and canned tomatoes can be used.
- Roasting tomatoes and including some of the roasted skins adds another flavor.
Salsa can be thickened by adding tomato paste
- Never thicken salsa with flour or cornstarch before canning as this may produce an unsafe product.
- Salsas can also be thickened after opening.
Green tomatoes or tomatillos (Mexican husk tomatoes)
- These can be substituted for red tomatoes or mixed with them.
- Tomatillos don't need to be peeled or seeded.
- Dry outer husks must be removed.
Peppers add color and heat to salsa recipes
Use high quality peppers:
- Don't increase the total amount of peppers in any recipe.
- You can substitute one type of pepper for another.
- Canned chilies can replace fresh.
- Peppers add color and range from mild to fiery in taste.
Hot peppers include: Jalapeno, Serrano, Cayenne, and Habanero and are usually small (1 to 3 inches long).
- When cutting or dicing hot peppers:
- Always use disposable gloves: oils in the peppers can cause extreme irritation to the skin.
- Don't touch your face, particularly around your eyes.
Mild peppers include bell, sweet cherry, pimiento and sweet banana and usually are larger (4 to 10 inches long) than hot peppers.
- You may choose a mild pepper when the recipe calls for long green chilies.
- Skin of long green chilies may be tough and can be removed by heating the peppers.
- When finely chopped, peppers don't need to be skinned.
Red, yellow, white, purple onions can be substituted for each other.
Adding acid is necessary to safely preserve salsa
Because the acidity level of tomatoes varies greatly, more acid must be added to produce a safe salsa.
- Commercially bottled lemon or lime juice or 5% acidity vinegar are Commercially bottled lemon juice or 5% acidity vinegar are used.
- Lemon or lime juice is more acidic and has less effect on the flavor than vinegar.
- Follow recipe directions for adding vinegar or bottled lemon or lime juice to home-canned salsa.
- Don't substitute vinegar for bottled lemon or lime juice, unless this substitution is given in the tested recipe, or an unsafe product may result.
If you are not using a tested recipe or like being creative with your salsa mixtures, store it in the refrigerator for up to a week or freeze it for up to one year. There are only USDA tested salsa recipes and processes for boiling water canning. There are no tested pressure-canning process for salsa.
Freezing will soften the salsa. Thaw in refrigerator and drain before serving.
Spices and herbs
- Add flavor and may be altered in recipes.
- For a stronger cilantro flavor, add fresh cilantro to the salsa just before serving because the hot processing temperatures may reduce the flavor.
Storing your canned salsa
Store home-canned salsa in a cool, dark place. For best quality and nutritive value, use within one year.
Reviewed in 2021