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Canning -- Miscellaneous

How do I know if a jar of home canned food is spoiled?

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When up-to-date guidelines, such as those outlined on this site, are followed exactly, there should be little concern about the quality and safety of your home canned foods. As with commercial packaged foods, it is always wise to examine any food before using it. When you take it from the shelf, check each jar to see that it has retained a vacuum seal and that no visible changes have taken place during storage. Unsealed lids indicate the possibility of spoilage. Spoilage produces gases that can break seals and/or cause the lids to swell. If a lid can be removed without the use of pressure to release a vacuum, do not use the product. Other signs of spoilage include mold, bubbling gases, cloudiness, spurting liquid upon opening, seepage, yeast growth, fermentation, sliminess or disagreeable odors. If you know that low-acids foods were improperly processed (i.e., in a boiling-water canner as opposed to a steam-pressure canner) do not use them under any conditions. If you suspect spoilage, dispose of the food without tasting it. Dispose of all spoiled foods in a manner that will prevent consumption by humans or animals. Source: Original FAQ posted at

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