Cereal Chem 54:597 - 604.  |  VIEW ARTICLE
Effect of Certain Nutrients on the Gas Produced in Preferments.

R. S. Ling and R. C. Hoseney. Copyright 1977 by the American Association of Cereal Chemists, Inc. 

A synthetic mixture of nutrients plus a buffer gives a yeast fermentation rate equal to that obtained with a flour. A mixture containing ammonium ion, phosphate ion, magnesium ion, sulfate ion, and potassium ion was required for maximum rate. Omitting any of those five ions retarded carbon dioxide production. Other ions, such as iron, zinc, copper, and manganese, and concentrated tap water had no effect on gassing rate. Chelating agents such as ethylenediamine tetraacetic acid likewise had no effect on gassing rate. Flour and/or nonfat dried milk had excellent buffering capacity. Fermentation rate was essentially equal with 60 or 100% flour in the brew. At least 7% sugar was necessary for a system containing no flour to have maximum fermentation activity for 4 hr.