Two types of biomass, switch grass and giant miscanthus, were subjected to pretreatment and acid hydrolysis. The pretreatments used on the grass samples included size-reduction, extraction and concentrated acid impregnation. BET surface area measurements indicated that the size-reduction and extractive-removal by water and ethanol resulted in changed surface areas compared to the as-received biomass samples. Analysis of the as-received and extractive-free samples showed that extractions with water and with ethanol removed inorganic compounds present in the as-received biomass samples. Under the same conditions of acid hydrolysis, the extractive-free samples displayed a greater extent of depolymerization of the cellulose and hemicellulose content compared to the as-received samples. Employing weight ratios of biomass to acid ranging from 1:2 to 1:10, 72% sulfuric acid was used. Examination of experimental results indicated that a biomass/acid weight ratio of 1:3 resulted in the greatest extent of depolymerization for both types of biomass.