This video is about the results of some chuck roast I canned 2 year ago January 2009. Still tastes great. Cooked in a pint mason jar for 45 minutes at 12 pounds pressure which is 2 pounds more than recommended for that size. For quart sized jars you would cook it for 15 min longer. What happens is in effect you are cooking and sterilizing the meat in its own juices. Theoretically as long as the seal is not broken and it still has a vacuum the meet will remain good In practice I will give it 2 or 3 years.