Program Book - Master Brewers Association of the Americas

P-143
Aspects of beer quality and extract recovery with modern yeast
management
REINER GAUB (1), Frank-Juergen Methner (2)
(1) Pall Food & Beverage, Bad Kreuznach, Germany; (2) VLB Berlin,
Berlin, Germany
Increasing costs for raw materials and energy are forcing brewers
to look into opportunities for increasing extract yield without
compromising quality. After fermentation yeast contains a
significant amount of extract. This extract can be recovered and
added back into the process by concentrating yeast with the modern
cross flow technique in combination with controlled Dia filtration.
This poster presents aspects of the process criteria which apply to
recovery of the extract and related analysis of taste active substances
during the process. The described technology for extract separation
is based on a ceramic cross flow technology with specific control
features. By controlling feed, cross flow velocity, permeate flow and
pressure trends in the process and adjusting the process to target
set points continuously at point of process results in an absolutely
gentle treatment of the yeast during the overall process. Most
important is the control of permeate flux and pressure in direct
relation to the cross flow speed and feed rate. By using Dia filtration
from a defined process point on, the yield of the process can be
increased significantly. In addition to extract a certain quantity
of taste active substances also are separated during the process.
The type and quantity of substances were measured at different
points of concentration during the process. Also the impact of Dia
filtration under different process parameters was investigated.
Finally the impact on taste stability was investigated in relation to
the blending rate of the extract to original beer and the blending
point. Results show that by applying a controlled process parameter
to a yeast concentration process in combination with Dia filtration
the process yielded by the brewing process can be increased without
compromising quality up to a 5% blending rate. Blending takes place
at final filtration. The ROI of the investment is typically