Muffy1938 – This is what I do when vacuum-sealing powdery foods in glass canning jars. First, I fill the jar with the powdered food to about a half-inch to one inch lower than I would normally fill it if I were vacuum-sealing something non-powdery (such as beans for example). Then I take a new paper coffee filter, (which I have cut into a bit smaller circle to fit inside the jar and cover as much of the top of the powdered food as I can), and place it right on top of the powered food inside the jar (That piece of coffee filter will stay in the jar and not be,removed until I later open the jar to eat the food). If I want to use one, I then add a new Oxygen absorber gently on top of the coffee filter piece. Next, I carefully wipe the rim of the jar and the glass near the rim (inside and out) with a slightly damp cloth. This is to remove any tiny particles of the powdered food that would otherwise prevent the seal. Then I place a clean, dry, powder residue-free, jar lid/flat on the jar’s rim, place the FoodSaver jar sealer attachment over it, and turn on the FoodSaver machine to pull a vacuum in the jar. That usually works. If not, I take the lid/flat off and re-wipe the jar rim and surrounding glass and the lid/flat to remove any visible tiny powdered food particles and try again. If the second try doesn’t work, I try again with a different new lid/flat. Sometimes it takes 3-4 tries before I can get all the tiny powdered food particles off the jar rim and lid/flat so the jar will seal. Occasionally, despite many attempts, a jar just plain won’t seal and, when I examine the rim closely, I usually see that there is some slight imperfection in the glass that’s preventing the seal from forming. When that happens, I put the powdered food in a different jar, and try again. I use the non-sealing jar for some other purpose (such as holding craft supplies, or extra screws and nails). After the jar of powdered food seems to have sealed, I keep it out in my kitchen for a couple of days and check it periodically to make sure it hasn’t come unsealed. Once I feel sure the seal will hold, I put it on my long-term pantry storage shelf. Another method you can try with powdered foods is to put them in a new, small ziploc bag that you seal almost all the way closed but not completely closed, then place that bag in the clean, dry glass canning jar, add an Oxygen absorber (if desired), wipe the jar rim and surrounding glass with a slightly damp cloth, place the lid/flat on the jar rim, attach the jar sealer device, and vacuum-seal the jar. I do that sometimes with very finely powdered foods. I have also heard of people taking powdered food that came in a small plastic bag, puncturing a few small holes in the top of the bag, placing the bagged food in the canning jar, and proceeding to seal the jar as I have described above – but without using coffee filter piece. Hope these ideas help! Oh, I forgot to mention that, in general, I have found that wide-mouth canning jars vacuum-seal more easily than do the regular-mouth jars. To get regular-mouth jars to seal, I usually have to place an extra lid/flat (turned upside down) inside the jar sealer attachment before I place that attachment over the jar and lid/flat that I’m actually trying to vacuum-seal. The little bit of extra pressure that extra lid/flat provides usually helps a lot.
