Annual Progress Report on Malting Barley Research March, 2002

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Methods.
Our malting schedule. We use the following protocol with the JW Micromalting
systems:
Steep: Air rest airflow rate of 30%, with 0% recirculation. All stages at 19ºC. 7
hours (h) wet, 8h air, 4h wet, 5h air, 2h wet, 2h air, and 2h wet (30h total).
Germination: Airflow rate of 30%, with 0% recirculation. 4 turns every 2h with a 30º
trim angle. 48h 18ºC, 24h 17ºC, and 24h 16ºC.
Kiln: All stages 40% airflow. 0% recirculation for stages 1-3, 50% for stage 4, and
75% for stage 5. 10h 49ºC, 4h 54ºC, 3h 60ºC, 2h 68ºC, and 3h 85ºC, with a 30 min. ramp
between stages.
Results.
High soluble protein levels. This schedule produced malt that was consistent with that
from our traditional system. However, the results of the 2001 AMBA Collaborative study
revealed that the malts produced in both our JW and traditional systems had elevated wort
soluble protein levels, compared to those from the other collaborators. We are, therefore,
still conducting research that is aimed at reducing the soluble protein levels in our
micromalts.
The Effect of air recirculation during germination. Researchers at the JW Maltings
had indicated that using less recirculated air during the steep air rests and germination
would decrease the grain modification rate. We have integrated this concept into our
malting schedule, but we needed to confirm this effect experimentally.
Multiple samples of each of four malting barley varieties (Harrington, Morex, Conlon, and
Robust) were steeped in one of the JW micromalting machines. Half of the samples were
then germinated in the same machine with 100% air recirculation, while the other half
were transferred to a second JW instrument and germinated with 0% recirculated air. All
of the samples were kilned with our normal 24-hour method. The quality parameters of
the finished malts are compared in Table 1.