Freeze dried instant coffee powder is just one of the ways that instant coffee can be made. It is made by flash freezing coffee and then dehydrating them. This results in a very concentrated form of coffee that can be reconstituted by adding water. You can also have spray dried instant coffee powder, which is made by drying the coffee with hot air and then grinding it into a powder. This type of soluble instant coffee powder is less concentrated and has a milder flavor.