Hey Alain,

About 20 years ago, I was drying about 100 lbs a week in a purpose made dehydrator, and selling about 95% of that (as fast as I could make it) at a tidy little profit. If you dry it to the point of not quite brittle (still a little bend to it, doesn't snap like a dry twig), it will last longer than you can leave it alone (I found a bag (brown paper) that was over a year old that was just fine). Vacuum seals, zip-lok bags, and tightly sealed jars are all good and well, but if you get it right, all you have to do is keep moisture and unwanted guests away from it, and it's good almost indefinitely.

Troy