A method of making an expanded or puffed high protein snack product or crisp comprises: a) mixing together water, protein and emulsifying salts in a mixer, b) heating the mixture in a pre-heated mixer and adding starch, c) mixing until all free water is absorbed, d) adding a preservative, e) chilling the mixture and cutting it into pieces and f) expanding the mixture by heating in a microwave. The microwave heating is carried out at a frequency of 800-1100MHz and a power of 10-75kW. The protein may be rennet casein and the starch may be derived from maize. Vegetable oil may be added in step a) or used to coat the pieces of step e). A snack food product is also disclosed.
