| Grain
Steeping of barley (credit Ian Oliver)
Unlocking the (diastatic) power of barley
Researchers have identified key genetic markers in barley which could help growers meet malting specifications and
lead to more efficient whisky production.
he AHDB funded
research, carried
out by the James
Hutton Institute
and SRUC, aimed
to identify genetic
markers for diastatic power (DP),
T
www.farmingmonthly.co.uk
which is the ability of a malt to
break down starches into simpler,
fermentable sugars, during the
mashing process.
This process is essential in the
production of grain whisky where
the mash consists of up to 90% of
unmalted cereal with the
remaining barley component
added in quantities sufficient to
breakdown the starch.
AHDB Cereal Product Quality
Scientist, Dhan Bandari, says the
work will help spring barley
growers meet the malting
specifications for the distilling and
brewing markets.
He says: “Varieties with higher
diastatic power can be used with
higher proportions of unmalted
cereal in grain whisky production,
thus enhancing the overall yield of
spirit. This potentially makes grain
whisky production both quicker
and cheaper, and increases the
number of barrels of spirit
produced per hectare of land
used.”
Grain whisky production
exceeds single malt production
and the market for high DP barley
is currently in excess of 100,000t
per annum, representing a
significant market.
Dr Bill Thomas, one of the
researchers who has worked on
the two year DP GENES project,
says: “Currently we tend to see
that varieties with high DP and
grain N tend to be low yielding, for
example, producing high diastatic
power malt with the current
preferred variety (Belgravia) yields
some 12% lower than new variety
Laureate which has a lower
diastatic power rating.
“The markers identified by this
project will therefore allow
breeders to combine high diastatic
power with high yield and so
produce premium barley which
could improve profit margins of
both growers and distillers.”
The research team used
historical data, including the AHDB
Recommended Lists, to collate
information on 100 spring and 100
winter barley lines, all with malting
quality potential and varying in
diastatic power potential. After
initial testing they then reduced
these lines to 24 lines of spring
and 24 lines of winter barley and
used those to identify and validate
candidate diastatic power genes.
While this work assessed
known spring and winter barley
lines the team felt they needed to
broaden the scope to include
untested lines. UK barley breeders
were asked to provide samples of
germplasm from their new barley
varieties, and the project was
inundated with over 150 samples,
a mix of spring and winter
varieties.
All the samples were then
grown on the James Hutton
Institute farm and the markers
used to predict high and low DP
lines. The accuracy of the
predictions was then tested by
sending the samples to the Scotch
Whisky Research Institute for
micro-malting analyses.
“The project has enabled us to
identify a group of genetic markers
associated with high diastatic
power which are compatible with
current breeding programmes,”
Bill explains. “This means that
varieties purposefully bred for high
diastatic power and high yield
could be available in the next five
years.”
The DP GENES project will be
showcased at this year’s Cereals
in Practice event, held at Saphock
Farm, Oldmeldrum, AB51 0EY on
6 July from 2.45pm – 6.30pm.
July 2017 | Farming Monthly | 25