It seems like the going rate for peanut butter is 2 years. Some people say as long as up to 5 years before the oil goes rancid. In our military rations it comes with peanut butter in small packages. I have eaten a 6 year old ration with peanut butter and it was still good. Most of the butter is pretty dry and does not have a lot of oil in it. I know that it is the oil that is the fat needed but what about pouring off/using the oil before it's life and re-canning what's left for another few years? Any thoughts? I might have a little project on my hands....