Disclosed are processes for liquefaction and saccharification of polysacharide containing biomasses having high dry matter content (>20%) and preferably possessing large average particle size. The polysaccharide containing biomasses are subject to enzymatic hydrolysis in a mixer that utilizes "free fall" mixing. "Free fall" mixing provides mechanical degradation of the biomass during hydrolysis and, in the case of lignocellulosic biomass, promotes movement of cellulase enzymes along cellulose chains, which improves enzymatic hydrolysis at high dry matter.