Powdered milk can be stored without refrigeration until it's converted to liquid, and it costs about half as much as liquid milk. Converting powdered milk to liquid milk is a simple process.

Step 1
Fill the pitcher with 2 cups of water. Add 1-1/3 cups of powdered milk. Stir vigorously until all the powder dissolves. Add the remaining water and stir again. Refrigerate until chilled.
Step 2
Stir the milk again, allow it to sit and then repeat. The protein in the milk blends more efficiently if you allow it to stand for a while before mixing again. You can use the milk directly after mixing, but it tastes best after four hours of chilling.
Step 3
Store your milk in a refrigerator and stir the milk vigorously before each time you use it. Some brands of milk powder have a tendency to sink to the bottom of the pitcher when left standing in the fridge. If you don't stir it, you'll end up with a watery beverage.