Whatever happened to canning nut meats?


In light of recent research looking at survival of Salmonella bacteria in low moisture foods, our concern has arisen about canning processes for nuts. Even after drying, the nuts may be exposed to moisture during canning processes. Although it is not likely that your particular batch of nuts is contaminated with Salmonella, the risk is present and exposure to moisture could be an issue.

Therefore Cooperative Extension, University of Georgia and the National Center for Home Food Preservation no longer offer a procedure for canning nut meats, with the single exception of our current procedure for green peanuts. USDA canning recommendations are unaffected, as they have no recommendations for canning nuts of any kind.

Alternatively, you can store nuts in sterilized canning jars without putting them through a canning process. To store nuts this way, it’s important that you heat and dry them first. Shell the nuts and spread them in a single layer on baking pans. Then place them in a 250°F oven until they are dry, but not brown or scorched, stirring occasionally. Allow them to cool at room temperature and simply put them in sterilized canning jars, covering with lids and ring bands.

Sterilizing jars provides extra protection against mold spores that could be on the jars. To sterilize jars, submerge them in boiling water for 10 minutes. Remove them from the water and sit them with open end down to allow them completely dry before filling with nuts.

Be aware that with any nuts, rancidity will eventually develop, making the product unappealing though not unsafe. Rancidity occurs in foods when fats or oils are exposed to oxygen over time, causing oxidation which leads to that yucky off-flavor. You might want to buy oxygen absorber packets to put in the jars. They will get rid of some of the oxygen, increasing their shelf-life. These packets are widely used in the food industry in products like bacon bits, jerky, etc.  Multiple sources can be found on the Internet.

4 thoughts on “Whatever happened to canning nut meats?

    1. nchfp Post author

      We cannot verify that the article you mention is a current state publication from LSU. It can be confusing when publications are not dated or when they remain available on the web even after their content has become outdated. Food science and food preservation research are ongoing endeavors that require a date to accompany proper publications because new information influences recommendations. The latest information leads us to the decision to not recommend canning nut meats.

    1. nchfp Post author

      You are correct in thinking that is a possible solution. Theoretically, it is possible. The problem comes in knowing what that process temperature (pressure) and time should be. Heat penetration studies must be conducted in order to determine a minimum processing time for any low-acid canning procedure. Such studies have not been performed for canning nut meats since recent research-based discoveries have informed us of previously unidentified bacterial concerns. To guess at a process time and guess wrong could result in foodborne illness from surviving bacteria, in this case Salmonella. If the nuts are also covered in water or brine, then there is the additional concern of botulism poisoning if the process is not determined with appropriate research. At this time, no one has identified funding or interest in doing this process development work to lead to a new recommendation. Alternatively, nut meats can be stored in a freezer in a dry pack in order to extend their quality over storage time. An advantage of the freezing method for preserving nuts is that the nuts will not go bad if the freezer goes out, though their quality will begin to diminish more rapidly than when frozen.

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