Free amino nitrogen (127.5mg/l) was available for fermentation by the starter yeast cultures (ie both
inoculum types) as shown in Table 1. Inoculum type
and fermentation time had significant effects on
FAN. Fermentation drastically decreased the FAN
levels in the wort for all samples to 37.5 and 44.5
mg/l for single and mixed cultures respectively in 72
hours. Much of the inoculum effect on FAN content
was observed within 48 hours of fermentation where
levels were reduced by more than 50% (50.5 and
54.5 mg/l for single and mixed cultures respectively).
According to Shimizu et al. (2002), FAN affects a
range of other fermentation factors, such as cell
growth, biomass, viability, pH, and attenuation rate.
However, high levels of FAN also serve as a recipe
for spoilage organisms to feed on. It is therefore
necessary that as much of it is used by yeast during
fermentation