The Gerlough method, developed in 1955 improved process economics by reducing the consumption of ethanol. Instead of 40% in certain steps, Gerlough used 20% ethanol for precipitation. This is especially used for Fractions II and III. In addition, Gerlough combined the two fractions with IV into one step to reduce the number of fractionations required. While this method proved less expensive, it was not adopted by industry because of this combination of fractions II, III, and IV, for fear of mixing and high impurities.