A method for preparing and using a combustible fuel product using sweet sorghum is disclosed. A sorghum variety high in sugar, high in biomass, and low in nitrogen is first processed to remove a majority of sugars therefrom. The remaining ligno-cellulosic residue, commonly known as bagasse, is converted into combustible pellets or alternatively stored for future pelletization. Storage is accomplished by first piling the bagasse on a hard surface. The bagasse is then compressed to form a compacted mass. Compression frees trapped air in the pile, hindering oxidative degradation by bacteria and other microorganisms.