The rate of isomerization of alpha acids to iso-alpha acids (the bittering compounds in beer) was characterized over a representative pH, wort concentration, time boiling and temperature range during the boiling portion of the brewing process.The tastes of beer typ are derivated from a judicios choise of row materials. Hops (Humulus lupulus L.), in particular, account, in adition for the bitter taste, for a delicate hoppy flavor in beer. Perhaps the most important class of hop compunds are the hops bitter acids, which are distinguished as alpha acids.. Because of the complex wort matrix and interfering interactions occurring during real wort boiling (i.e., trub formation and α-acids/iso-α-acids complexation), this investigation on α-acid isomerization was performed in wort solution as a function of time (60−120 min), pH variation (5.1-5.8) and wort original gravity (10-14oPlato).The experiments demonstrate that the rate of isomerization depending of beer matrix, the performers of wort kettle and the variety of hops.
MENU
