THE INFLUENCE OFHAFNIA PROTEA (OBESUMBACTERIUM PROTEUS)ON BEER FLAVOUR

Abstract
Numerous strains of Hafnia protea (originally Obesumbacterium proteus) were grown in brewer's wort in the absence and presence of Saccharomyces cerevisiae. The presence of H. protea gave rise to increased levels of n-propanol, isobutanol, isopentanol, dimethyl sulphide, dimethyl disulphide and 2,3-butanediol in finished beer. Concentrations of dimethyl sulphide and dimethyl disulphide varied according to the bacterial strains, but the increased levels of fusel alcohols and 2,3-butanediol were strain-independent.