Achieving Enhanced Hop Utilization by Fractional Wort Boiling

摘要

For the first time, the continuous mash filtration system consisting of four rotary disc filters (modules 1 to 4) allows the simultaneous frac-tioning of the wort flows regarding their chemical and physical quali-ties. This leads not only to time savings of 30% per brew but also to the more efficient utilization of raw materials, especially in terms of hops and their chemical transformation of a-acids into iso-a-acids (isomer-ization). A series of experiments was performed at lab scale (5 L vol-ume). The wort of each module in comparison to a preboil wort of a lauter tun was analyzed and boiled with hops separately. The results show an increase of the isomerization rate by using the worts from modules 3 and 4. This is caused by the pH value, the original gravity, and further influencing factors. In comparison to the preboil wort from a lauter tun, the isomerization rate of the worts (modules 3 and 4) is on average about 85% higher.