Enzymes covalently immobilized on highly porous materials are demonstrated to have very high biocatalytic activity and good recyclability, exemplified by Candida antarctica Lipase B (CAL-B). Polymerized high internal phase emulsions (PolyHIPEs, see figure) are developed for covalent grafting of proteins (enzymes) via the reaction of the protein surface lysine residues with active ester moieties in the monolithic material.