The enzymatic hydrolysis cost highly depends on the enzyme dosage used, the substrate used, and the pretreatment method used [15] and [16]. Therefore, the enzymatic hydrolysis of corn stover using dry pretreatment and Youtell #6 enzyme was optimized to give the minimum cost of stover sugars. The solids loadings, cellulase dosages, and the reactor scales were considered in the hydrolysis study. The sugar yield obtained at different conditions was incorporated into the Eq. (10) as described in Supplementary Materials to calculate the stover sugar hydrolysate production costs. The conditions which could obtain a relative lower sugar production cost was chosen for the following experiments. The pretreated corn stover was used directly for enzymatic hydrolysis without any other detoxification process. All the enzymatic hydrolysis trials were performed in duplicates and the average data were reported.