Abstract
Diacetyl is normally considered to be an off-flavor in
lager beer, and its removal prolongs the overall brewing
process. Here, the effects of fermentation temperature
(9, 12, and 15°C), initial wort pH (4.8, 5.1, and 5.3),
and wort free amino nitrogen (FAN) content (222, 252,
287, and 366 ppm) on diacetyl formation and removal in
lager beer fermentations were studied in order to develop
an enhanced model for predicting fermentation progress
(alcohol content, biomass, and pH) and diacetyl
concentration. The relationships between model
coefficients, temperature, pH, and FAN were calculated,
and models predicted fermentation and diacetyl profiles
with a good fit (overall relative mean square error less
than 10.1%). The model was validated, and also applied to
a larger-scale fermentation involving a different wort
and yeast strain by adjusting model coefficients. The
model can be used for predicting diacetyl concentrations
and for brewing process parameter optimization in
industrial fermentations.
Original language | English |
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Pages (from-to) | 90-99 |
Journal | Journal of the American Society of Brewing Chemists |
Volume | 73 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2015 |
MoE publication type | A1 Journal article-refereed |
Keywords
- diacetyl
- FAN
- fermentation
- mode
- vicinal diketone
- yeast