Observations on the Effect of Lipids on Head Retention

Modification of the conventional method of filtering an infusion mash was found to increase the content of extractable head-negative substances, including phospholipids, in unhopped wort. The additional constituents were also present in the corresponding hopped worts and in beers at rack but largely disappeared during subsequent processing. Much of the additional fatty material was removed when finings were added: this process induced a substantial rise in head retention. The positive role of lipids in brewing processes is discussed.