Microfiltration studies with a modified membrane filterability procedure.

Sudarmana, D.L., Goldsmith, M.R., Hinh, A.H., Pecar, M.A., Hawthorne, D.B. and Kavanagh, T.E.

Abstract
An improved method for determining the suitability of beer for membrane microfiltration is described. It is based on an existing method, whereby the maximum quantity of the beer in question that can pass through a membrane filter of a standard size and type is measured, but in recognition of the fact that for practical purposes the membrane filterability of a beer is that which applies in the absence of the yeast cells and particles removed by the kieselguhr (or equivalent) and polishing/stabilizing/particle trapping filters, it incorporates sample preparation procedures which enable the membrane filterability of the bright beer to be predicted using samples of rough matured beer or even green beer, which are degassed and centrifuged to remove yeast and coarse particles. Treatment with gel removing enzymes (xylanase and/or beta glucanase) or isinglass finings before centrifugation may also be beneficial, as may heat treatment and dilution. The use of the procedures described enables the likely membrane filterability of the bright beer to be predicted sufficiently far in advance to allow action to be taken to improve it if necessary. It is also possible to use this method to evaluate the effects of raw materials, enzyme preparations, etc., on the membrane filterability of beers brewed using them.
Keywords : beer filterability measurement membrane prospect