The National Center for Home Food Preservation acknowledges the concerns raised by consumers regarding the use of 4% vinegar acidity for canning. We would like to provide the following important points for your consideration if you have utilized vinegar in your home canning practices:

Recipe Recommendations: It is crucial to note that recipes, including those from the National Center for Home Food Preservation (NCHFP) and the United States Department of Agriculture (USDA), were extensively tested and recommended the use of vinegar with 5% acidity. Currently, it is strongly advised against using vinegar with lower acidity levels (<5%), as it may not be sufficiently strong to ensure the safety of the canned products. Always remember to check the vinegar label for its acidity level.

Evaluating Canned Food Products: If you have used vinegar with lower acidity (less than 5%) in your canned food products and you followed a validated recipe, we recommend considering the following:
    i) If your canned food has been preserved for less than 24 hours using 4% vinegar, it is advisable to     store the jars in the refrigerator to maintain the safety and quality of the product.
    ii) If your canned food has been preserved for more than 24 hours using 4% vinegar, it is advisable to     discard the product.

Please remember that ensuring the safety of your home-canned products is of utmost importance.

Following tested and approved recipes, including the use of recommended vinegar acidity, is crucial for maintaining the safety and integrity of the preserved foods.