Powdered milk generally lasts for 18 months according to manufacturers' "best by" dates, but it can often remain usable for much longer if stored properly. The USDA states that powdered milk can be stored indefinitely. An unopened package can be safe to use for 2 to 10 years after the "best by" date.
Factors Affecting Powdered Milk Shelf Life
Several factors influence how long powdered milk retains its quality:
- Packaging: Unopened packages, especially those vacuum-sealed, offer the longest shelf life.
- Storage Conditions: Store powdered milk in a cool, dry place, away from direct sunlight and moisture.
- Exposure to Air: Once opened, the powder is exposed to air and moisture, which can degrade its quality and flavor more quickly.
- Fat Content: Whole milk powder, with its higher fat content, may not last as long as non-fat dry milk powder because fats can go rancid.
Powdered Milk Shelf Life Estimates
| Condition | Shelf Life (Relative to "Best By" Date) | Notes |
|---|---|---|
| Unopened Package | 2-10 years+ | Assuming proper storage (cool, dry, dark place). |
| Opened Package (Properly Stored) | Several Months | Store in an airtight container in a cool, dry place. |
| Reconstituted Milk (Refrigerated) | Up to 5 Days | Similar to fresh milk. |
Signs of Spoilage
Even though powdered milk may be "safe" indefinitely, its quality can deteriorate. Here are signs it may no longer be desirable to use:
- Off-odor: A rancid or stale smell.
- Discoloration: Yellowing or browning of the powder.
- Clumping: Significant clumping that doesn't easily break up.
- Unpleasant Taste: If reconstituted milk tastes sour or otherwise off, discard it.
Tips for Maximizing Shelf Life
- Store in an airtight container: Once opened, transfer powdered milk to a tightly sealed container.
- Keep it dry: Prevent moisture from entering the container.
- Avoid temperature fluctuations: Store in a consistently cool environment.
- Use dry utensils: Always use a dry spoon or scoop when measuring powdered milk.
- Consider vacuum sealing: For long-term storage, consider vacuum sealing individual portions.
