Annual Progress Report on Malting Barley Research March, 2002

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Table 1. A comparison of the malting quality of barley samples germinated with 0% or
100% air recirculation.
Fine
Wort
Variety or Percent Moisture Extract Wort Wort Protein S/T DP
AlphaBetaamylaseglucan Quality
Selection recirc'n adjusted (%) Color Clarity (%) (%) (ASBC) (20ºDU) (ppm) Score
Conlon 0 OS,d1,d2 81.6 1.8 1 5.37 49.1 88 71.9 93 39
Conlon 100 OS,d1,d2 81.7 1.6 1 5.29 47.5 97 76.1 86 43
Robust 0 OS,d1,d2 78.7 2 1 6.17 47.3 147 57.1 196 27
Robust 100 OS,d1,d2 78.6 1.9 1 6.17 47.3 155 56 195 32
Harrington 0 OS,d1,d2 81.6 1.4 1 5.22 47.1 87 66.6 94 32
Harrington 100 OS,d1,d2 81.4 1.3 1 5.16 45 97 68.1 88 41
Morex 0 OS,d1,d2 80.5 2.4 1 6.15 53.1 104 66.6 109 36
Morex 100 OS,d1,d2 80.2 1.9 1 6.23 54.2 131 73 83 40
Only the Diastatic Power values varied when the air flow was altered. The levels
increased markedly when the air flow was raised to 100%. Varying the air had no effect
on the moisture retention of the barley samples. Other than the DP values, the amount
of air recirculation during germination had little effect on the finished malt quality.
The effect of moisture levels during germination. The quality of malts prepared in
the JW micromalting units is affected by moisture fluctuations, and especially by
desiccation, during malting. It is thus important to monitor the moisture levels of the
barley during germination and to understand how moisture changes that occur
throughout the malting process affect the quality of the finished malt. An investigation
of how the out-of-steep (O-S) and germination moisture levels affected the malt quality
has been carried out. The moisture levels of Harrington barley samples were adjusted at
O-S, and every 24 hours afterwards, until germination was completed. The quality
values of the resulting malts are displayed in Table 2.
Table 2. The effect of germination moisture levels on Harrington malt quality
parameters.
Wort
Protein
Alphaamylase
Betaglucan
(ppm) FAN
Fine Coarse
S/T DP
Moisture Extract Extract F-C (%) (%) (ASBC) (20ºDU)
43% 81.0 79.0 2.0 5.37 48.7 89 63 296 218
44% 81.3 79.1 2.2 5.47 50.2 84 68 314 215
45% 81.2 79.4 1.8 5.47 49.0 85 64 256 212
46% 81.3 79.8 1.5 5.66 50.7 98 72 108 222
Statistical tests revealed that the Fine Grind Extract and Wort Clarity parameters were the
only ones that were not affected by the germination moisture level. All of the other grain