When hiking and going on long camping trips, space efficiency is important. There is only so much room available to store clothes, food and camping equipment. A common remedy as far as food is concerned is to buy food that has been dried into a powder that can be pack tightly. To turn the powder into a meal, you just need to apply water. I’ve carried powdered milk on trips for cereal and other meals. The powdered milk doesn’t spoil and tastes like normal milk.
I used to think powdered milk along with other powdered foods were totally synthetic. It turns out I was wrong. Liquid milk can be powderized with a spray dryer. Turing milk into a powdered form is actually a very practical way to preserve milk. The powdered milk retains much of the nutritional value of fresh milk and can be reconstituted by adding water. However, the equipment to make powdered milk is rather expensive and is only feasible on the industrial level.
The spray drying process involves various nozzles, gasses, spray and gas flow patterns all depending on the kind of solids and desired consistencies of the finished product. The first step in spray drying milk involves filtering and testing the raw milk. It is then sent to an evaporator where about a third of the water is removed. The 50% solid milk is then moved to a separator which removes different amounts of butter fat depending on the desired milk.
Next, the milk is sent to a drying tower to be dried by a spray nozzle. This involves shooting the milk into hot air, which will leave the solid milk particles on the ground. The solid milk is then coated with lecithin to allow it to combine with water more easily. After that it is packaged and ship. Apart from milk, teas, spices and pharmaceutical drugs are also spray dried.