Adsorption of hop compounds from beer on to activated carbon

This study investigated the use of powdered activated carbon (PAC) for the removal of hop compounds, particularly isomerised alpha acids (iso acids), from beer. The average iso acid adsorption capacities of the adsorbents in descending order were activated carbon manufactured from wood, coal, peat and coconut. Iso acid adsorption capacity was found to be strongly correlated with increasing pore volume and surface area in the mesoporous region. A good correlation between the adsorption of colour and iso acids from beer existed. Carbon treatment had little effect on the majority of beer quality indicators however, trace volatile compounds were adsorbed differentially, with both hydrophobicity and molecular size appearing to be important.