Powdered milk, also known as milk powder, dried milk, or dry milk, is created by removing water from liquid milk. This dehydration process transforms fresh milk into a long-lasting, easily stored powder.
The Process of Making Powdered Milk
The manufacturing process generally involves two key steps:
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Evaporation: First, the milk (often skim milk, containing about 91% water) undergoes evaporation. This involves boiling the milk under reduced pressure and low temperature. This process concentrates the milk by removing a significant portion of its water content.
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Spray Drying: The concentrated milk is then sprayed into a chamber of hot air as a fine mist. This rapid evaporation further removes moisture, transforming the milk into a powder. The resulting powder is then collected, often packaged, and ready for consumption.
Different methods exist, but spray drying is the most common industrial technique.
Variations in the Process:
- Type of Milk: The starting material can vary, using whole milk, skim milk, or even buttermilk, resulting in different nutritional profiles in the final product.
- Additional Ingredients: While not always included, some manufacturers might add sugar or other ingredients to enhance taste or stability.
Several sources confirm this process: The provided text mentions evaporation and spray drying as key steps. Numerous online resources and Wikipedia detail this manufacturing method. Many other sources corroborate the two-step process of evaporation followed by spray drying.
Storage and Shelf Life
Powdered milk's extended shelf life is a major advantage. Proper storage is vital to maintain quality. One source mentions that non-fat powdered milk stored in plastic-lined paper bags at temperatures between 70°F and 90°F has a two-year shelf life.
