Replacement of kettle hops with (reduced) isomerised hop extracts: implications for beer bitterness and flavour stability

摘要

Pre-isomerised hop extracts do not contain polyphenols. Thus, their application could adversely affect flavour stability. This study on similar pilot beers demonstrates that exclusive bittering with iso-α-acids during wort boiling is not to the detriment of flavour stability. In comparison with conventional pellet hopping, advanced bittering is at least ‘neutral’ to flavour stability and markedly positive in respect of bitterness quality. Flavour deterioration is further delayed when tetrahydroiso-α-acids are included post-fermentation. These observations raise the question on the relevance of the reducing power of kettle hops. Advanced hopping presents an alternative in view of refined bitterness and enhanced flavour stability.