SCIENCE
IT WILL ALL COME OUT IN THE WASH
IN THIS PIECE ADAM JOHNSON, EUROPEAN TECHNICAL SALES AT MURPHY & SON, LOOKS AT ENZYMES AND THEIR ROLE IN THE DISTILLING PROCESS.
M
alt is a fantastic
of fermentable extract whilst retaining
thing. The maltster
the flavour and aroma characteristics
has prepared for
essential to malt whisk(e)y {1}.
the distiller a self-
This author does not want to get into
disassembling starch
spelling debates, but will use whisky for
package, where the package even
everything for the remainder of this piece.
assists in producing wort for fermentation
Pale ale brewing malt and pot still malt
by forming the filter bed.
may have some nuanced differences, but
The enzymes included in the grain are
they are both essentially well-modified,
capable of completely degrading the
plump & pale malts.
starch at ambient temperatures {1}. This may be the case but in distilling,
For Scottish grain distilling, high Diastatic
a compromise is always found during
Power malts are used. This is because
processing as you are trying to meet
other unmalted grains are used to
various and sometimes conflicting goals.
provide the majority of the starch.
Before looking at exogenous enzymes it is worth looking at what is already
They lack the required enzymatic
available from malted barley.
activities & without external assistance they will not be able to convert this starch
As the barley grain is coaxed into
to fermentable substrate.
germination through the malting process the starchy endosperm degrading
High DP malt enables the distiller to
enzymes are produced: αalpha-
convert this whilst remaining compliant
amylase, endo-betaβ-1,3:1,4 glucanases,
to the Scotch Whisky Act.
limitdextrinases, endoproteases &
One of the key distinguishing features
Xylanases. (F.G Priest, GG Stewart
between wort and wash production vs
Handbook of Brewing). Unmalted barley
wort and beer production is the wort boil
contains βbeta-amylase and peptidase
& lack of it in distilling.
enzymes. From an enzymatic point of view this
distillersjournal.info
Malting barley for distilling is a balancing
has a dramatic effect on the wash
act of trying to achieve maximum levels
composition as enzymes remain active
SUMMER 2021
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