"Character of wheat beers
As a result of the typical aroma components
which are formed by wheat beer yeast, these
beers also have typical aroma impressions
which differ considerably from bottom
fermenting beers :
The typical wheat beer aroma is mainly influenced
by 4-vinyl-guaiacol (0.2-3.2 ppm,
mean value 0.5-0.7 ppm), whose flavour in
large quantities fits into higher alcohols and
esters (flavour threshold 0.7 mg/I).
The formation of 4-vinly-guaiacol (clove
aroma) is aided by
• low mashing-in temperatures,
• long 45 °C rest,
• a mash pH of 5.7 - 5.8, no mash acidification,
• at least 40 % part barley malt,
• the strain of yeast,
• fermentation temperatures of 20-24 °C,
• one or two yeast cycles and
• early harvesting of the yeast."
The gold standard Hefeweiss mash is the maltase mash. Which features a 45c rest for ~60 minutes. After the 60 minutes the mash pH is still above 5.7.
Duration of 45 °( rest (min) Aroma impression
0 10 25
phenolic 1.2 2.1 3.3
estery 4.1 3.4 2.6
yeasty 1.8 2.6 2.8
A rest of at least 10- 15 minutes should be
observed to achieve a clear phenolic aroma
Mash acidification suppresses the release of the
ferulic acid and thus the formation of 4-viny~
guaiacol. On the other hand, an extended 45c
rest reduces the occurrence of an estery aroma.