How long does powdered milk last?

Nonfat powdered milk lasts about 18–24 months in its retail package and up to roughly 20 years sealed in #10 cans with oxygen absorbers; whole-milk powder keeps far less.

	Powdered Milk
Unopened	18–24 months in the original package
Opened	About 3 months in an airtight container; mixed milk 3–5 days in the fridge
Ideal storage	Cool, dry and dark; it absorbs odors and moisture easily.
Long-term	Nonfat dry milk in sealed #10 cans with oxygen absorbers: up to about 20 years.

Storage tips

Whole-milk powder contains fat and goes rancid much sooner.
Off flavors appear well before it becomes unsafe.

Signs it has gone bad

A rancid smell, often described as crayons, putty or old paint (oils, nuts, nut butters, whole-milk powder)
Mold on the surface or under the lid
Off colors or a sour smell
Hard clumps in sugar or salt are only moisture and are harmless; break them up

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