ASBC_Fishbone_VIb.pdf

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PROCESS CONTROL FOR MALTING PROCESSES IMPACTING BEER FLAVOR STABILITY:
STORAGE TO GERMINATION
Storage
Steeping
Sapporo & ESR.....higher steep-out moistures
(43 vs. 37%) gave malt with
higher levels of free radicals. Likewise longer
germination times
(4 vs. 6 days).
Lower malt storage temps slows
LOX inactivation (-)
N
2
/CO
2
purging before milling (+)
Increase [polyphenols & reducing substances] in malt
by :
a) higher temp steep waters,
b) shorter wet steep times,
c) lower temp on last day of germ, and
d) prolonging germ time by one day.
N
2
/CO
2
storage (+)
RG values higher with longer steeps (43.4 vs.
47.2% moisture) & showering at germ
start....extracts more of Fe & melanoidins.
Pre-soak barley in 1% lactic before steeping..inactivates LOX.
LOX activity decreases with storage time (+)
Effect on Beer
Flavor Stability
Narziss:
higher proteolytic modification caused by higher
water contents in the germination process resulted in higher
[SI staling compounds] in finished beer.
Narziss:
higher proteolytic modification
caused by higher water contents in the
germination process resulted in higher
levels [SI staling compounds] in
finished beer.
Practices which limit embryo growth (+) as this is location
for both LOX and lipid substrate...beware of over-
modifying malt as this promotes LOX production of
hydroperoxides.....undermodified malts
favors less DMS as well.
Optimized lactic acid microflora
during malting ....add yogurt?(+)
Suntory
has shown that malt which is
more highly modified
has accelerated production of OH
-
radicals and H
2
O
2
in wort
during forced oxidation and lower EA values in beer i.e. less
flavor stability. Mechanism believed to be higher levels of
melanoidins and iron in more modified malt.
Germination
Germination
ASBC No. VIb
(Casey;
June/05)

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