Food Canned With Lower Acidity Vinegar Deemed Unsafe

Foods stored more than a day using 4% vinegar or lower should be discarded

Many New Hampshire residents enjoy canning to preserve local fruits and vegetables, but a recent announcement from the University of Georgia requires many to change their process.  

Recently, The National Center for Home Food Preservation announced new guidance for those who use vinegar in their home canning. 

The Center strongly advises against using vinegar with lower acidity levels (less than 5%), as it may not be sufficiently strong to ensure the safety of the canned products.  They remind home canners to check the vinegar label for its acidity level.

What should I do with canned foods that are stored in lower acidity vinegar? 

 If you have preserved food using vinegar with lower acidity (less than 5%),  and you followed a validated recipe, the Center recommends:

  • refrigerate foods from jars that have been preserved for less than 24 hours using 4% vinegar or less. 
  • discard food from jars that have been preserved for more than 24 hours using 4% vinegar or less. 

UNH Extension Food Safety Specialist Ann Hamilton notes the change will be news to many. " This reduction in acidity in vinegar will be a real challenge when making pickled products at home. All tested recipes are made with 5% vinegar. It is important that those who make pickled food, relishes, and salsas with vinegar, check the acidity level before purchasing. The bottom line is that the safety of pickled products depends on vinegar with 5% acidity."

To learn more, UNH Extension encourages you to review materials from the National Center for Home Food Preservation at

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Food Safety Field Specialist
Extension Field Specialist, Food Safety
Phone: (603) 447-3834
Office: Cooperative Extension, Taylor Hall, Durham, NH 03824