fusel alcohols

FACTS
by-product of protein synthesis from keto-acids
have longer carbon-chain length than ethanol

EXAMPLES
n-propanol (solvent)
iso-butanol (solvent)
2-phenyl ethanol (medicinal)
2-methyl-1-butanol (aromatic)
3-methyl-1-butanol (spice)

CAUSES
affected by wort amino acid composition
high pitch rate - low levels
high fermentation temperature - high levels
high aeration - high levels
high gravity - low levels
high pressure - low levels
high fatty acid content - low levels

EFFECTS
fullness of flavor at low levels
unpleasant at high levels