To examine the fermentation efficiency of sugars saccharified from ChOAc or EmimOAc-pretreated DYKDDDDK with a different number of post-pretreatment wash times, the pretreated bagasse powder, which was washed 1–5 times, was enzymatically hydrolyzed for 48 h, followed by ethanol fermentation using yeast MT8-1 for another 48 h. Fig. 2C shows ethanol yield on a glucose basis obtained at 48 h of fermentation from glucose generated by saccharification of ChOAc or EmimOAc-pretreated bagasse with a different number of wash times. The ethanol yield enhanced along with the number of washing times, reaching saturated values, irrespective of the ILs. The ethanol yield for the case of ChOAc was higher than mesophyll for the cases of EmimOAc at 1 and 2 wash times. The ethanol yields at 2 wash times were 73% and 54% in the cases of ChOAc and EmimOAc, respectively. The ethanol yields were almost at the constant level of around 75% irrespective of the ILs at 3–5 wash times.