TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The method further comprises contacting the peroxide compound and quat. ammonium compound prior to adding the peroxide compound and quat. ammonium compound to the fermentation process. Preferred Process: The fermentation process further comprises adding nutrients to inoculant, fermentable sugar and process water; or directly to the fermentation vessel; adding peroxide compound and quat. ammonium compound to the contacting product which comprises ethanol; separating the ethanol from the product; and feeding remaining product to a beer-well or a thin stillage tank and adding peroxide compound and quat. ammonium compound to the beer-well or thin stillage tank. The fermentation process is batch fermentation; and the peroxide compound and quat. ammonium compound are added to the fermentation vessel prior to adding the fermentable sugar to the fermentation vessel. The fermentation process is a continuous fermentation process; and the peroxide compound and quat. ammonium compound are combined and added as a single composition to the yeast propagation step to produce the yeast inoculum or during the contacting step. Preferred Components: The peroxide compound and quat. ammonium compound are added separately to fermentation process. The inoculant is a yeast inoculum produced by contacting a yeast starter culture and a nutrient composition in a propagation tank. The fermentable sugar is derived from corn using a dry grind or wet mill process; sugarcane; sugar beet; or molasses-based fermentable sugar. The peroxide compound is added at 10-1000 ppm. The quat. ammonium compound is added at 10-1000 (preferably 50-500) ppm. The peroxide compound is selected from hydroperoxide, organic peroxide, inorganic peroxide and/or peroxygen-releasing compound, preferably hydrogen peroxide. The quat. ammonium compound is alkyl dimethyl benzylammonium chloride; dioctyl-dimethylammonium chloride; didecyl dimethyl ammonium chloride; diallyl-dimethylammonium chloride; di-n-decyl-dimethylammonium chloride; cetylpyridinium chloride; and/or benzethonium chloride. The feedstock is a cellulose feedstock. The feedstock has carbohydrate content of greater than or equal to 1 wt.%.