Canning Nut Meats

A recent discussion on canning nuts and recipes containing nuts prompted me to contact NCHFP for help in clarifying a few things.  Many recipes call for nuts as an ingredient and some of those in the discussion thought the recipes may no longer be safe and just had not been pulled from NCHFP website.    I received the answer from them and hope it will be of help to all of you.  As I said before, canning nuts alone is no longer recommended, but if a recipe calls for nuts then the recipe is safe as long as it is a tested recipe.

Dear Kathy,

Thank you for your interest in the National Center for Home Food Preservation. Regarding your question:

There has been a big discussion in a canning group that I am in concerning the safety of canning nut meats and recipes containing nuts.  I hope you can help me clarity the issue.  I explained to them that nchfp no longer recommends water bath canning nut meats alone but that they should freeze them.  I gave them the following link for a reference.

Whatever happened to canning nutmeats?

 Some of them believe that recipes like conserves calling for nuts are now no longer safe to make and can and that nchfp just hasn't pulled the recipes and updated their web site.  I explained that if you are using a tested recipe from nchfp or the Ball Blue Book and the recipe calls for nuts then that particular recipe is ok to can.  Can you please give me an answer on this to clarify this issue.   

You are correct, it is only particular canning procedure for a dry pack of shelled nut meats we withdrew:

I explained to them that nchfp no longer recommends water bath canning nut meats alone

This was not intended to be any recommendation regarding other products such as conserves that might contain some nuts. We only recommend canning recipes, procedures, and process times that have a scientific, research-based determination. Let's consider our recommendations for conserves with nuts, such as Apple Conserve: http://nchfp.uga.edu/how/can_07/apple_conserve_powder.html for example -- these recipes, procedures, and canning processes were developed with that called for amount of nuts. Rather than just nuts alone, there are other ingredients that influence the characteristics of the final product. Apples are an acid food and lemon juice is a strong acid, increasing the acidity of the final product. Pectin and sugar combine with this acid and fruit to make a gel, which reduces the water activity of the final product. These characteristics make a difference in the canning process. For a more detailed explanation of how canning processes are determined, please read this backgrounder: http://nchfp.uga.edu/publications/nchfp/factsheets/heatprocessingbackgrounder.html .

We also update recommendations when new research reveals previously unknown concerns. In the case of canning nut meats, concerns arose due to the increase in Salmonella problems in some nut products such as we have seen over the last few years. In just the past few years, there has been new research about different species of Salmonella and their tolerances for some drier (low water activity) conditions. Based on this information, canning nutmeats in a dry pack could be potentially hazardous using the directions we formally had if any condensation or moisture pockets formed inside the jar. That previous canning process was really a way to create a vacuum-sealed jar and there is no documentation for any microbial sterilization that might have been taking place.  So, without the science to support it, and in the face of concerns from microbiologists should moisture condense inside the jars, we no longer have a recommendation for canning nutmeats at home in the dry pack in a boiling water canner (or by any means)​​.  We are unable to study this issue in home canning at this time.  There are other options today for vacuum packaging of dry shelled nutmeats than there were when that process was first published.

As an aside, nutmeats stored in a freezer in a dry pack should not go bad or spoil once the electric goes out.  Nuts do not even have to be stored in the freezer; it is a way of extending the quality over storage time but not necessary for safe storage.

You can also contact Ball to find out their testing protocol for their recipes ( http://www.freshpreserving.com/contact-us ). Ball does conduct product testing, but not everyone who writes canning recipes does; you can always try contacting authors and companies in order to find out their testing protocol (or lack there of). We suggest using canning recommendations only from reliable sources who have conducted product testing.

Best wishes,

Kasey Christian