I own my own freeze dryer and with this I seal a lot of food in glass jars. The best way I have found to seal in bulk is something I built. I took an old pressure cooker with a good seal on the lid. I removed all the pressure cooking fittings on top of the lid. I then installed a vacuum gauge with a tee fitting and a ball valve to relieve the vacuum later in the process. I also installed a fitting with a 1/4 flare end. I then attach the flare connection to a vacuum pump used for air conditioning work with a refrigeration hose. This is it!
I put my jars inside the pressure cooker with the rings left loose! I can put in as many jars as the cooker will hold. I close the lid and valve and turn the pump on. When I reach 25″ of vacuum, I open the ball valve to relieve the vacuum and then I turn the pump off. I tighten the rings and I’m finished. I will even vacuum seal a jar with unused oxygen absorbers to prevent them from going bad, and maximize their effectiveness. The pump and hose can be purchased from Harbor Freight. This is a decent pump for this process and will work quite well. My cooker will hold 8 qt. jars in one setting. My pump will process these all at once. If there are problems with the lid not sealing properly you could use 3/4″ Plexiglas with a silicone mat for the seal. Warning: the plexy is very pricey (24″x24″ is over a $100). This will only work with dry goods. (NO wet food allowed!) When I open the jar I can use my fingers, but if you use an opener try not to bend the lid. That way it can be used over and over with no problems. – Keith in Kansas
JWR Adds: After completing the vacuum process, be sure to test the seal of each lid (by tugging up, gently), before putting on the jar rings. This is because once in a while you will find a jar where the vacuum does not hold, and that jar will have to be re-processed.