Bhat et al.
processȱtoȱproduceȱfineȱqualityȱtableȱvinegar.ȱInȱthisȱprocess,ȱwoodȱbarrelsȱ
wereȱusedȱandȱfilledȱwithȱalcoholȱfermentingȱliquidȱtoȱapproximatelyȱ¾ȱ
full, which was provided with holes at the end of the barrel just a few
inches above the liquid surface. These holes were left open and covered
withȱaȱfineȱscreenȱ(Cruessȱ1958).ȱ
Peppler and Beaman (1967) standardised the method of adding 20-25% of
fresh vinegar into the barrel in order to acidify the liquid to the point of
optimum growth for the vinegar bacteria. They reported that the bacteria
settledȱintoȱtheȱliquidȱfromȱtheȱairȱandȱformedȱaȱgelatinousȱslimeȱlayerȱ
on the top of the liquid. The liquid was then fermented for about 1 to 3
months at 70ºF to 85ºF.
Maazaand Murooka (2009) reported that the Orleans process relies on
the natural acetic acid bacteria present in the raw material, or makes the
use of a seed culture from a previous production batch. It was found
that the bacteria, was belonging to the species Acetobacterxylium , and
showed growth on the liquid-air interface of the medium. Due to the
oxygen requirement, the species were able to produce cellulose, a thick
mat of a gelatinous substance containing bacterial cells and cellulose was
developed over time on the top of the liquid. And the oxygen was moving
into the mat used for the oxidation of ethanol into acetic acid. As a result
of this, the concentration gradient within the barrel was produced with
aȱcontinuousȱdiffusionȱofȱfinishedȱvinegarȱdown-wardsȱandȱaȱdiffusionȱ
ofȱ ethanolȱ towardsȱ theȱ mat.ȱ Theȱ acetificationȱ processȱ tookȱ aȱ longȱ timeȱ
compared to more recent methods, with a production rate of about 1%
acetic acid per week.
Raspor and Goranovic (2008) reported that the vinegar produced by the
Orleans process was of high quality due to the slow production process
thatȱpromotesȱtheȱdevelopmentȱofȱflavourȱandȱaroma.ȱItȱwasȱfoundȱthatȱ
thisȱwayȱofȱprocessingȱprovidesȱaȱconstantȱavailabilityȱofȱfinishedȱvinegar.ȱ
But the drawback of this process was the long time required, resulting in
high costs per volume produced even though the investment in equipment
and the running costs were low.
The Generator process
Early in the nineteenth century, a vinegar-making system called the
trickle method (now called generator fermentation or quick process) was
developedȱbyȱGermanȱchemistȱSchutzenbachȱinȱ1832.ȱInȱthisȱprocess,ȱtheȱ
bacteria were grown and formed a thick slime coating around a non-
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