I guess a better question is what is the life span of a properly dehydrated food in a mylar bag with an o2 absorber? I have some rice, beans, etc done already but nothing I dehydrated.
One key is rotation. Don't just buy/make food for long term storage once. Make it year long and consume old stock on the shelves. Initial hit to the finances is greater at first, then spreads out, but in long term it neutralizes as you replace what you eat. Let you projected needs determine how much you hold in reserve.
That way you keep an eye on it's performance, ability to eat it, what you like to eat, etc.
The lifestyle is best not left at 'buy and forget'. That way you avoid a disaster in x number of years when you really need it, only to find it spoiled.
Has not been mentioned in a long time here, but the Mormans are experts in this area. Self-Reliance - store.lds.org
They have a lot of local resources that will assist non-LDS members also.
Bulk food such as rice and beans can be placed in a sterile 5 gal food quality container with a Gamma lid. Just before sealing place sufficient dry ice on top to completely replace the normal atmosphere with CO2.
you didn't say how long you wanted to store the food. Weeks, months or years??
Oxygen is the enemy of food storage.
Mylar bags and Oxygen absorbers is what I would do.
This is how I store most of my bulk prep food.
you order the Mylar bags and oxygen absorbers together. Place your food in the bag, drop a couple of O2 Absorbers in, vacuum out what air you can and iron it shut.
there are hundreds of videos on youtube about how to do this.
Food grade buckets slowly leak CO2, so you'll need mylar bags for that. Also, be careful what kind of rice you store. Brown rice goes bad fairly fast (about a year) because of its delicate oils. Parboiled rice is kinda considered the best, it has 80% of the nutrients of brown but a 2 year shelf life. It's about a dollar a pound at Wal Mart.