Foams suitable for such uses as landfill coverage, frost protection, volatile emission control, gas control in mining, are composed of a hydrolyzable protein and a pre-gelatinized cationic modified starch along with other ingredients. The foam concentrate can be made at ambient temperature, is stable over time, can be easily tailored to achieve a desired foam stiffness and drain time characteristic over wide ranges, and can be easily diluted at ambient temperature to produce a foamable composition.