MALTING QUALITY TRAITS - Canadian Malting Barley Technical ...

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Chapter Four
The attributes listed above suggest that, in order to achieve their quality potential,
Canadian varieties need to be malted in a different manner than barley of other origins.
In general, Canadian malting barley can be processed relatively easily and can achieve
desirable modification rapidly under a broad range of processing conditions. Canadian
barley carries little or no dormancy due its genetic make up and growing conditions.
Canadian barley is ready for malting shortly after harvest; therefore there is no need for
any treatments to overcome dormancy. The uniform kernel size and thin husk enable
Canadian barley to obtain even hydration at steep with shorter simpler steep cycles.
Good germination energy and strong vigor enable the barley to achieve a high degree
of chitting at steep and to obtain rapid vegetative growth and fast modification advancement,
without applying gibberellic acid or other additives. High enzyme levels enable
the resultant malt to have acceptable levels of enzymes and FAN (free amino nitrogen),
even under less than desirable malting conditions. The relatively higher barley protein
content requires some attention from the maltster during processing in order to control
the protein solublization and to develop desirable levels of soluble protein and malt color.
Although a wide range of processing programs are used in commercial malting plants
in Canada and U.S., most of the malting cycles use six to seven days of processing time
to complete a production cycle. An example of the processing program for malting of
the two-rowed Canadian variety, AC Metcalfe, is given in Table 1 below for reference:
Table 1: Processing Conditions for Malting Canadian AC Metcalfe
Process Stage Steeping Germination Kilning
Scope of the
processing
conditions
Water Temp: 12-16 °C
Target moisture:
43-44 %
Duration: up to 48
hrs
Aeration: 15 minutes
out of every 30
minutes 1.5-1.6m 3 /
minute/tone at wet
period. Maintain
good CO 2 evacuation
at air-rest at rate of
5m 3 / minute/tone
Example 40 hours (8 hours
Wet-10 hours Dry -8
hours Wet-10 hours
Dry -4 hours Wet)
@14 °C
Air-on temp: 12-15 °C
Duration; 3.5 - 4 days
Air flow: 9-10 m3/
min /tone
For bed depth at 0.8-
1.3m
Day 1 and Day 2
@14°C; Day 3 and
Day 4 @ 13°C
Air on temp:
Free dry at 50 to 68°C
for 10-12hrs
Heating at 68-80°C for
2-3hours
Curing at 80-85 °C/
3-4 hours
Duration: up to 24 hrs
Air flow: 60-80m 3 /
min/tone for bed
depth at 0.8-0.9m
A 21 hour cycle with
a 4-hours of curing
phase at 80-83°C
At steeping, the barley is usually steeped at a temperature ranging from 12 to 18°C
for a total cycle time of up to 36- 48 hours with simple cycles (two water immersions
or three immersions separated by one or two dry ventilated air-rests). Target cast
moisture is approximately 45% and the chitting rate should be above 80% at the end
of steep. Whether using multi-immersion steeping or spray steeping, the cycles should
be chosen so that the barley grains hydrate evenly and chit uniformly by the end of the
steep period. It is important to recognize that Canadian barley varieties take up water
fast, and they have strong germination vigour. This can lead to excessive CO 2 and heat