Fed batch fermentation for
amla wine production
The amla extract medium was fed
with sugar syrup (70% TSS) to re-adjust
the TSS to 20% every time. Fed-batch
fermentation is a production technique
in between batch and continuous
fermentation. A proper feed rate, with the
right component constitution is required
during the process32-33. This system worked
very well by eliminating the effect of high
sugar concentration, at the start of
fermentation and produced an alcohol
content of 16.6% v/v at the end of 9 days
of fermentation. The rate of utilization of
substrate and alcohol production
increased immediately after feeding the
batch with fresh dosing of sugar (Fig. 8).
Maturation of amla wine
The ageing of the wine improved
the wine characteristics in terms of clarity
and proved to be very useful in bringing
significant reduction in undesirable
alcohols like n-propanol, n-butanol, isobutanol,
isoamyl alcohol as well as total
acids. On the other hand the desirable
components including ethyl acetate
increased with the ageing in both the
containers, however, the degrees of
improvements were more in wooden
barrel than in glass bottles. The storage
in oak wood also brought about an
improvement in phenolics, aroma, taste
and stabilization of the wine colour (Table
1). The wine matured in oak wood barrel
was also adjusted to be the better after
tasting by a panel of five judges
(Table 2). Oak is the most commonly used
wood for barrels used for ageing quality
wines and spirits known to improve wine
characteristics and colour stability