Powdered food has a few problems, as far as I'm concerned:

* It is highly processed, which can affect nutrition in a time when you really need nutrition. For example, flours may last 6-12 months, whole grains a lot longer.

* It has more surface area exposed to air and light, which reduces livespan and nutrients. Even if it's sealed in the ideal container, how long did it take to get there? What did it lose in the meantime?

* The need for water for reconstituting and digesting it.

* Destruction of nutritional content, molding in poor packaging.

* Refrigeration may help extend life --- don't have refrigeration under survival conditions?

Smaller containers of powdered foods are probably acceptable for adding to other foods (eggs, flours, spices, etc), but large containers are probably a false economy for a small family.

Sue