Preserve it! Series: "Dry Canning" Dried Foods is Not Actually Canning, and Potentially Unsafe
Internet practice is not a recommended preservation method.
Another preservation process making the internet rounds recently is so-called “dry canning,” in which dried foods such as beans, grains, pasta, nuts, flour, etc. are put into canning jars and then the jars are heated in a low oven. Some directions call for applying the lids first, others have lids applied when the jars come out of the oven. Either way, dry canning is not actually canning and is potentially unsafe.
Even dried foods contain residual moisture – depending on the food, it could be as much as 30%. Placing any food in the oven will cause moisture to migrate towards the surface of the food, where it can evaporate and cause condensation on the inside of the jar. Pockets of moisture can also develop inside the food as the moisture moves toward the surface. The moisture pockets and condensation can lead to the growth of mold, pathogens (such as Salmonella), and even bacterial spores (such as Clostridium botulinum), all of which can make you ill (or worse).
Quality-wise, the heat used in dry canning can increase oxidation, resulting in nuts and grains going rancid more quickly.
For long-term storage of dry foods, there are plenty of options, including vacuum sealing machines (with adapters for jars), oxygen absorbers, freezing, and more. Utah State University Extension’s website has information on storing many types of dried foods, as well as a comprehensive downloadable booklet on storing food for emergencies that covers different storage options (see link below).
For further information visit the National Center for Home Food Preservation (NCHFP) or Utah State University.
Brought to you by the UC Master Food Preservers of El Dorado County
Last updated July 2025