Biomass conditioning for bioconversion is a necessary step before starting the enzymatic degradation of the substrate. This stage generally includes screening of impurities, size reduction, and moisture content adjustment. Moisture content is considered an important chemical property that has extensive influence on the substrate physical properties. The overall accessibility of biomass-degrading enzymes to the substrate can be affected by modifying the moisture content in biomass. In spite of the significance of this property the information available in the literature on the hydrolyzability of pretreated lignocellulosic substrates differing in moisture content remains ambiguous. Moisture content reduction by drying or pressing is frequently included in a bioconversion process to maximize the solids concentration in the final reaction mixture or to minimize the possibility of microbial contamination. This study describes the effect of different drying regimes on the enzymatic hydrolyzability of a steam-exploded rice straw and an organosolv-pretreated hybrid spruce pretreated at low, mild, and high severity.