Preserve It! About That Vinegar—Read The Label!

By UCCE Master Food Preserver Laurie Lewis

Originally appeared on November 27, 2024 in the Mountain Democrat

There’s a concern that, in the past few years, we have been seeing white vinegar with 4-percent acidity on store shelves. All our tested, safe recipes for home food preservation use 5-percent acidity vinegars. This one percent drop makes a big difference in preserving and pickling your foods safely. Vinegar below 5-percent is not adequate to control microbial growth in your home canning.

Here’s the problem: the U.S. Food and Drug Administration “only” requires vinegar to contain at least/at minimum 4-percent acetic acid (not 5-percent). There are some specialty vinegars which may range up to 8-percent, some quite expensive. Recipes generally are not written for these high percent vinegars (usually because of cost, color, cloudiness, or sharpness).

Safe, 5-percent vinegar is still for sale, but may be shelved next to vinegars that are not considered safe for canning and preserving. Read. The. Label.

Most likely the reason we are now seeing 4-percent vinegar is a cost factor with the manufacturers.
There is a vinegar called “Pickling Vinegar Base” that is only 2.5-percent acidity. The acidity is reduced by the addition of water. The color of the product and shape of the container looks just like regular 5-percent vinegar. It may also include salt as well as sugar. Do not use this for your home canning; it is for refrigerator pickles as the label says.

What if you find a vinegar with the percent acidity listed as “grains”? This refers to the measure of vinegar to water. The “grains” are divisible by 10 and are easy to match the percentage. 50-grain vinegar is the same as 5-percent vinegar. 40-grain vinegar is 4-percent, and so on.

What if you have used a vinegar with 4-percent acidity? It is recommended by the National Center for Home Food Preservation (NCHFP), if you have used vinegar with less than 5-percent acidity following a research-tested recipe:

1. If your canned food has been preserved for less than 24 hours using 4-percent vinegar, it is recommended to store the jars in the refrigerator to maintain the safety and quality of the product, as these foods are not considered safe to store at room temperature. These foods should be eaten within a month.
2. If your canned food has been preserved for more than 24 hours using 4-percent vinegar, it is recommended to discard the product. To ensure the safety of your home-canned products, do not use homemade vinegar or vinegar of unknown acidity in your home canning! The acidity of homemade vinegar is not consistent. Do not dilute the vinegar unless the recipe specifies.

Apple Cider Vinegar and Distilled White Vinegar are the two most common vinegars. They remain stable for up to two years. Store in a cool location, away from light. Discard after “best used by” date as recommended by manufacturer, or discard after one year for best quality. Specialty vinegars such as red or white wine vinegar, malt vinegar, balsamic, and flavored vinegars should only be used when a research-based recipe says to use one.

National Center for Home Food Preservation has some wonderful (free) pickling recipes for those last-of-the-growing-season vegetables and fruits you may still have in the garden or something you bought too much of at the grocery: nchfp.uga.edu/how/pickle. Now with your new knowledge of vinegars, perhaps you could try some of those recipes. Happy, safe home canning!

The UC Master Food Preservers of El Dorado County are a great resource for answers to your food safety and preserving questions. Leave a message at (530) 621-5506 or email us at edmfp@ucanr.edu. For more information about our program, events, and recipes, visit our website at ucanr.edu/sites/mfp_of_cs/. Find us on Facebook, too (UCCE Master Food Preservers of El Dorado County)!