This time of year, you might be eager to find the best way to make your bounty of pecans, almonds, chestnuts, walnuts or peanuts last through the holiday season and beyond. While canning is a go-to for preserving, let’s not forget that some foods don’t fare so well as a canned product. USDA has never had a home canning recommendation for canning a pack of only nut meats, and the NCHFP website only has a recommendation for canning green peanuts from past work at the University of Georgia.
A previously (and no longer) recommended canning process for "canning" dry nutmeats found in So Easy to Preserve from the University of Georgia is no longer included in the new edition of the book. It was actually just a way to create a vacuum-sealed jar and there was no documentation for any microbial sterilization that might have been taking place. Questions about the risk (even if a low risk) of some bacterial growth if condensation of moisture occurred inside the jars from canning in boiling water led to re-consideration of this advice for sealing jars. Compared to when this was first published years ago, now there are other ways to vacuum pack dry, shelled nut meats at home without heating in boiling water.
Nuts tend to store very well by proper drying and storing in air-tight containers in a cool location. Refrigerated (at 32-45°F) nuts will maintain quality for one year and frozen (at 0°F) nuts will maintain quality for 1, 2, or even 3 years depending on the type of nut. See this publication from the University of California for more specific information about harvesting and storing different types of nuts.
While we know of no tested recommendations for canning pecan pie filling, another common request, you can easily make your pecan pies as usual, cool rapidly, and then freeze briefly before packaging for long term freezer storage (pies will be easier to wrap after freezing). Stored at 0°F, frozen pecan pies are expected to last 3-4 months.
Conserves are a delicious way to use up smaller quantities of nuts. By definition, conserves are jam-like products that contain nuts, raisins, and/or coconut. These conserve recipes allow you to choose your preferred nut type: Apple Conserve, Apricot-Orange Conserve, Cranberry Conserve, Damson Plum- Orange Conserve, Grape Conserve, and Plum Conserve.
Are you wondering why it’s ok to can nuts in conserves but not by themselves? The recommendation we withdrew was just one procedure for canning a jar of all nutmeats in a dry pack. There is nothing wrong with canning foods with nuts in them, if tested that way. Other recommendations (like conserves) were developed with a called for amount of nuts along with other ingredients which influence the characteristics of the final product. Let's consider Apple Conserve, for example: Apples are an acid food and the lemon juice is a strong acid; if other ingredient proportions are kept as expected, the final product should remain acid enough for boiling water canning. Furthermore, in this conserve, the 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 what the process recommendation should be, and were taken into consideration for that recipe when a canning process was determined.