HISATO IMASHUKU (1)
(1) Asahi Brewers, Ltd., Japan
We have developed two new technologies for efficient and flexible
wort boiling. They can reduce the total evaporation ratio during wort
boiling, without the increase of undesirable or excessive flavors from
malts or hops. Moreover, the isomerization of hop α-acids is improved.
They are the “DMS-rest” and the “Pre-Isomeriser & Evaporator (PIE).”
The removal of DMS is limited by the conversion from DMS-precursor
(DMS-P), not by the evaporation of free-DMS itself. When the wort is
heated up, the supply of steam is stopped, and the wort stands at a high
temperature. This is the DMS-rest. During the rest, DMS-P is converted
to free-DMS without more supply of steam. After the rest, the wort is
boiled for a short time. Free-DMS is evaporated immediately, because it
has already converted enough from DMS-P. However, using the DMS-rest
method, some flavors from hops cannot be sufficiently removed, because
of their higher boiling temperatures. And shorter boiling time leads to
insufficient isomerization of α-acids. Therefore, we developed equipment
for boiling hops with hot water, separately from wort. We named it PIE.
The energy consumption in PIE is slight, because the size is 1/50 of
the wort kettle. After evaporation and isomerization in PIE, the hops is
added to wort. PIE also improves the utilization of hops. We suppose
that enough heat load and good extraction by strong agitation in PIE
contributes to the isomerization of α-acids. By 2009, we have applied
PIE and DMS-rest to our 5 breweries on a commercial scale. In 2010, we
can reduce costs for energy by $1.1 million and for hops by $0.3
million. In the combination of DMS-rest and PIE, it is possible to take
both of the optimums for wort and hops, at the same time, and
independently of each other.
Hisato Imashuku graduated with a degree in agricultural chemistry
from the University of Yamaguchi, Japan. He began employment with Asahi
Breweries, Ltd. in 1989 as a technical staff member in the brewing
section. After he had worked at several breweries and in the laboratory,
he was transfered to the Ibaraki R&D Promotion Office in 2001. He
has been working at the Nishinomiya R&D Promotion Office, Production
Technology Center, Asahi Breweries, Ltd. since 2008.
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