Powdered milk does not go bad, but it does begin to lose its flavor after some time. Powdered milk can be stored for 2 years before it begins to develop a stale flavor.
The shelf life of powdered milk can be extended by storing it in airtight containers. Powdered milk should be stored at room temperature, but cooler temperatures also aid in extending its shelf life.
Powdered milk does not need to be refrigerated. Milk is evaporated to create a powder, and the powdered milk has a low moisture content which accounts for its long shelf life.
Powdered milk was invented in 1802.