<p>A method for producing a fermentation product in a fermentation system from biomass that has been pre-treated and separated into a first component and a second component is provided. The method comprises preparing a slurry comprising: supplying the first component to the fermentation system; and providing an ethanologen to the fermentation system. The method also comprises adjusting the pH of the slurry to a range of about 4.5 to about 6.5, maintaining the first component and ethanologen in the fermentation system at a temperature of between about 25 and about 37 degrees Celsius, and recovering fermentation product from the fermentation system. The ethanologen is supplied to the fermentation system in a concentration of less than 2 grams of ethanologen on a dry basis per liter of slurry. The biomass comprises lignocellulosic material. The first component comprises pentose, which can comprise xylose. The ethanologen is capable of fermenting xylose into ethanol.</p>
