I’ve tried the tested and recommended salsa recipes that are printed in your “Preserving Tomatoes” publication. However, my family doesn’t like them because they have so much vinegar added. Why do you have to add that much vinegar?

Most canned salsa recipes combine onions, peppers and tomatoes with acetic acid, in the form of either vinegar or lemon juice. The amount of acid is critical to the salsa’s safety. A proper amount of acid will reduce the pH, which is a measure of the food’s acidity. For safe salsa, the pH of the vegetable ingredients should be less than 4.6.

Foods with a pH less than or equal to 4.6 are labeled “high-acid” foods. Those with a pH greater than 4.6 are “low-acid.” This distinction is very important because only high-acid foods can be processed safely in a boiling water bath. Low-acid foods always must be processed in a pressure canner; if not, they can support the growth of the potentially harmful bacterium, Clostridium botulinum.

That’s why it’s important to use only tested recipes when canning your own salsa. Food scientists have evaluated a tested recipe to ensure that the amount of acetic acid in combination with the other ingredients will sufficiently reduce the mixtures pH so that it can be safely processed in a boiling water bath. The processing times also have been tested to ensure that harmful microorganisms are destroyed.

What types of acids can I use to make my salsa safe?

When canning salsa use only bottled lemon juice or vinegar that is at least 5 percent acetic acid (acidity). Never use homemade vinegar or freshly-squeezed lemon juice because the level of acid present is not known.

Bottled lemon juice tends to be more acidic than vinegar. It also has less effect on the overall flavor of the product in which it is used. Equal amounts of bottled lemon juice can be substituted for vinegar in recipes calling for vinegar. Vinegar, however, should not be used when a recipe calls for lemon juice.

What type of vinegar can I use to make salsa?

Any type of vinegar can be used as long as the product label states that it is at least 5 percent acidity. If this is not stated on the label, do not use the vinegar for canning or pickling. White vinegar has a tart flavor but will not discolor the salsa. Cider vinegar has a milder flavor but tends to change the salsa’s color.

Balsamic and other seasoned vinegars are more expensive than white or cider vinegar, but they are safe to use. Because the acidity of homemade vinegar is often unknown, do not use it to can salsa.

Can I change the amount of ingredients in my salsa recipe?

No. The only modifications that you can make safely in a salsa recipe are the amounts of spices used. Changing any other ingredient or amount could lead to an unsafe product. However, if you have a favorite salsa recipe that you are interested in canning and the proportion of low to high acid vegetables does not compare equally to a tested recipe, it can be tested with a pH meter to insure its safety. If interested, K-State Research and Extension can test it for pH. A fee will be charged.

Where should I store my home-canned salsa?

Store home-canned salsa in a dry and dark area. The temperature of the storage area should be between 50 degrees and 70 degrees. As a rule of thumb, the higher the storage temperature, the shorter the shelf life of the product. Its shelf life is between 12 and 18 months.