FACTORS INFLUENCING FORMATION OF A YEAST HEAD BY BREWING YEASTS

Yeast head production is dependent upon the relative rates of (a) arrival of yeast at the surface of the fermenting liquid, (b) its incorporation into a foam and (c) the inherent rate of foam collapse. Under (a), strains of Saccharomyces cerevislae and S. carlsbergensis vary in their ability to adhere to carbon dioxide bubbles which transport them to the wort surface. With regard to (b), the incorporation of yeast into a wort foam increases its stability; the variation in foam stabilizing properties between different strains of S. cerevislae and S. carlsbergensis is dependent on the degree to which they are transported to the surface and thus incorported into the foam. The importance of a wort with good foam stabilizing properties for satisfactory yeast head production during fermentation is emphasized. 1969 The Institute of Brewing & Distilling