Release and evaporation of volatiles during boiling of unhopped wort.
The release and evaporation of volatile compounds was studied during boiling of wort. The observed parameters were boiling time, boiling intensity, wort pH, and wort density. The effect of every parameter was discussed and approached chemically, with an eye on beer-aging processes. The results indicated that pH highly influenced the release of flavor compounds and that the formation of Strecker aldehydes was linear with boiling time. However, because of evaporation of volatiles, information about the applied thermal load on wort is lost when using a volatile heat load indicator. The thiobarbituric acid (TBA) method, which includes the nonvolatile precursors of volatile aging compounds, proved to be a more reliable method to determine all kinds of heat load on wort. Finally, it was discussed how the obtained insights could help to understand the mechanism of beer aging.
Centre for Malting and Brewing Science, Faculty of Bioscience Engineering, Catholic University of Leuven, Kasteelpark Arenberg 22 box 02463, 3001 Heverlee, Belgium. david.deschutter@biw.kuleuven.be
David P
DP
De Schutter
Daan
D
Saison
Filip
F
Delvaux
Guy
G
Derdelinckx
Jean-Marie
JM
Rock
Hedwig
H
Neven
Freddy R
FR
Delvaux
D001515:Beer / Q000032:analysis; D002523:Edible Grain / Q000737:chemistry*; D005511:Food Handling / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D013858:Thiobarbiturates / Q000032:analysis; D013997:Time Factors; D014835:Volatilization
D013858:Thiobarbiturates; C029684:thiobarbituric acid