An improved model for prediction of wort fermentation progress and total diacetyl profile

Kristoffer Krogerus (Corresponding Author), Brian Gibson, Eemeli Hytönen

Research output: Contribution to journalArticleScientificpeer-review

4 Citations (Scopus)

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 languageEnglish
Pages (from-to)90-99
JournalJournal of the American Society of Brewing Chemists
Volume73
Issue number1
DOIs
Publication statusPublished - 2015
MoE publication typeA1 Journal article-refereed

Fingerprint

Diacetyl
wort (brewing)
diacetyl
Fermentation
fermentation
prediction
amino nitrogen
brewing
beers
Nitrogen
Temperature
alcoholic fermentation
off flavors
Biomass
nitrogen content
temperature
Yeasts
Alcohols
yeasts
biomass

Keywords

  • diacetyl
  • FAN
  • fermentation
  • mode
  • vicinal diketone
  • yeast

Cite this

@article{1df76bc0c79d4071aed6b343f3d5d1a3,
title = "An improved model for prediction of wort fermentation progress and total diacetyl profile",
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.",
keywords = "diacetyl, FAN, fermentation, mode, vicinal diketone, yeast",
author = "Kristoffer Krogerus and Brian Gibson and Eemeli Hyt{\"o}nen",
year = "2015",
doi = "10.1094/ASBCJ-2015-0106-01",
language = "English",
volume = "73",
pages = "90--99",
journal = "Journal of the American Society of Brewing Chemists",
issn = "0361-0470",
number = "1",

}

An improved model for prediction of wort fermentation progress and total diacetyl profile. / Krogerus, Kristoffer (Corresponding Author); Gibson, Brian; Hytönen, Eemeli.

In: Journal of the American Society of Brewing Chemists, Vol. 73, No. 1, 2015, p. 90-99.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - An improved model for prediction of wort fermentation progress and total diacetyl profile

AU - Krogerus, Kristoffer

AU - Gibson, Brian

AU - Hytönen, Eemeli

PY - 2015

Y1 - 2015

N2 - 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.

AB - 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.

KW - diacetyl

KW - FAN

KW - fermentation

KW - mode

KW - vicinal diketone

KW - yeast

U2 - 10.1094/ASBCJ-2015-0106-01

DO - 10.1094/ASBCJ-2015-0106-01

M3 - Article

VL - 73

SP - 90

EP - 99

JO - Journal of the American Society of Brewing Chemists

JF - Journal of the American Society of Brewing Chemists

SN - 0361-0470

IS - 1

ER -