Date of Award

Spring 1947

Degree Type

Thesis - Restricted

Degree Name

Master of Science (MS)




The culmination of this research problem is the net result of the authors' curiosity developed over a period of five years while employed in the laboratories of the Pabst Brewing Company. During this time the author had become quite familiar with the brewing industry and its many problems. The role that the vitamin and amino acids play during a fermentation has always been a curiosity to the brewer. The finished wort which the brewer uses for his fermented beers is composed of many constituents of a complex nature. Little is known about the yeast nutritional requirements from this wort. These essential food materials are derived ultimately from the barley. Under the action of proteolytic enzymes operative during the malting and mashing operations, the proteins of the barley are decomposed into simpler compounds. One of the most obvious properties of wort is that it contains not one but very many different nitrogen nutrients. Investigating a problem of this type it is essential to identify the growth constituents and assess their nutrient value. However, the brewers' wort is so complex in nature that to set a value on any one component in the presence of others is an impossibility. This problem can be approached however, by the introduction of a synthetic wort of known composition. Here one can study the behavior of yeast on a single nutrient or groups of nutrient constituents with the ultimate objective of formulating a medium which will satisfy the requirements of yeast.