re: Walnut, it not always about the lumber.

Canning the walnuts are as simple putting them on a cookie sheet in a 180 degree oven. After about 30 minutes I stir them up and back into the oven. After about 90 minutes I tast them to make sure they don’t have any moisture.
I then spoon them into mason jars that were in the oven for at least part of the time to heat them up

Fill the jar and put on the lid some-what tighly but not locked down. The air in he jar escapes as it gets hot and after about 15 minutes I take them out and tighten the lid. They then vacuum seal as they cool down. Any not sealed become the first ones to be eaten.

I’vr got some jars over 2 years canned and the nuts are as fresh as when I first canned them. No spoilage.