Large-scale study on beer filtration with combined filter aid additions to cellulose fibres

Abstract

Kieselguhr or diatomaceous earth is the most commonly used filter aid for beer filtration. However, lately the use of kieselguhr has come under increased criticism. Some of the reasons for this are cost of disposal, limited resources and hazards to health from diatomite powder. One alternative to filtration with kieselguhr could be cellulose. Cellulose can be regenerated several times, is easy to dispose of, bears no health risks and as a renewable raw material is widely available. Previous single filtrations with cellulose were not satisfactory. A pre-clarification of wort and green beer with silica sol was used in this work to improve the haze of the filtered beer. Furthermore, silica sol was added to the cellulose mixture for body-feed during filtration. This represents a new field of application. When adding silica sol, filtrate haze was reduced in both applications. The intensity of this effect was dependent on how, when and where the material is added. Another future alternative could be rice hull ash because of its similarities to kieselguhr. © 2011 The Institute of Brewing & Distilling.