Powdered milk, in its dry, unopened form, doesn't need refrigeration and has a very long shelf life. According to the USDA, powdered milk can be stored indefinitely. This means that if stored correctly, unopened powdered milk does not have a set expiration date.
However, the question refers to refrigerated powdered milk, which typically implies that the milk has been reconstituted (mixed with water) and is now in liquid form. Let's consider both scenarios:
Dry Powdered Milk (Unopened or Opened)
- Shelf Storage: As mentioned, dry, unopened powdered milk has an indefinite shelf life according to the USDA, if it's stored properly in a cool, dry place, away from humidity, and in an airtight container.
- Opened Dry Powder: Once opened, it's best to use the powdered milk within a few months for best quality. Although it may still be safe, the taste and nutritional value might decline over time. Again, store opened powdered milk in a cool, dry, and airtight container.
- Refrigeration is not required: Refrigeration of dry powdered milk is unnecessary. It will not extend its shelf life.
Reconstituted Powdered Milk (Liquid Form)
When powdered milk is mixed with water it becomes a perishable product and should be handled like fresh milk.
- Refrigerated: Once reconstituted, the liquid milk should be refrigerated immediately and consumed within 5-7 days, just like regular fresh milk.
- Smell and Taste: Always check for any signs of spoilage, such as a sour smell or taste, before consuming.
- Storage: Store reconstituted milk in an airtight container in the refrigerator.
| Milk Form | Shelf Life | Refrigeration Required |
|---|---|---|
| Dry Powdered (Unopened) | Indefinite (USDA) | No |
| Dry Powdered (Opened) | Several months (for best quality) | No |
| Reconstituted (Liquid) | 5-7 days | Yes |
Key takeaway: The indefinite shelf life applies to the dry, unopened product only. Once reconstituted, powdered milk needs refrigeration and has a limited shelf life similar to that of regular milk.
