A method of making a powder of serum extracted from a Greek style yogurt is disclosed. The total solids concentration of the serum is increased to at least 35% by weight to produce a concentrated serum. The concentrated serum is crystallized by adding lactose crystals whose average size is less than 100 microns. The crystallized serum is then spray dried to produce a serum powder. The resulting powder is non-hygroscopic, less likely to form lumps in storage, retains the initial characteristics of the serum and is of sufficiently high quality to be fit for human consumption.
