A number of β-glucanase active enzyme preparations were successfully immobilized either by adsorption on Duolite S-761 phenol-formaldehyde resin or covalently on silanized Spherosil XOB-075 porous silica beads to obtain remarkably stable active biocatalysts. A Duolite immobilized β-glucanase could be employed for continuous treatment of barley wort in a packed-bed column reactor to decrease viscosity and to improve filtrability. A Duolite immobilized cellulase that exhibited no detectable Avicel hydrolyzing activity could be applied for batch treatment of wheat starch process water. The same enzyme when covalently bound on Spherosil was, however, capable of hydrolyzing microcrystalline cellulose in a recirculating fluidized-bed reactor.