From UAF Cooperative Extension Service
Some vinegar sold in Alaska stores may not be acidic enough for use in home canning, according to the University of Alaska Fairbanks Cooperative Extension Service.
Vinegar used in nonpressurized water-bath canning, such as pickles or chutney, should have 5% acidity. Some vinegar now in Alaska stores has only 4%. The acidity percentage is listed on the label.
The higher acidity is necessary to prevent the growth of deadly botulinum bacteria.
The level of acidity in a pickled product is as important to its safety as it is to taste and texture. If the vinegar is too weak, soft or slippery pickles will occur. These symptoms indicate microorganisms were not destroyed.
If you have used vinegar with an acidity of less than 5%, the National Center for Home Food Preservation recommends the following:
If your canned food has been preserved for less than 24 hours using 4% vinegar, it is recommended to store the jars in the refrigerator to maintain the safety and quality of the product.
If your canned food has been preserved for more than 24 hours using 4% vinegar, it is recommended to discard the product.
For more information, contact Health, Home and Family Development agents Leslie Shallcross at firstname.lastname@example.org, 907-474-2426 or Julie Cascio, email@example.com, 907-745-3677.