Wine Production : Vine to Bottle - Vinum Vine

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WINE PRODUCTION
fermentation takes. Accordingly, managing the temperature can be
quite a tricky exercise. A winemaker may decide to start a vat fairly
cool, at say 20 °C, and allow it to rise naturally to around 30 °C to
aid extraction. In the latter stages, the vat may be cooled to 25 °C or
so, to ensure complete fermentation to dryness. In the cool
underground cellars of regions like Burgundy, the temperature of
small vats or barrels can be self-regulating. Cooling equipment
may be required for larger vats. Wine can be pumped through heat
exchangers to reduce (or increase) temperature. Stainless steel
tanks are now commonly wrapped with water or glycol cooling
jackets. Alternatively, they may be cooled by showers of cold water
running down the outside. In concrete or wooden vats a metal cooling
device (drapeau) can be inserted or built in.
9.3.3 Extraction
The traditional process for red wines is for the grape mass to
be fermented in open vats. The solids and skins rise to the surface
with the CO 2 and create a floating cap. This is a disadvantage
because the skins need to be in contact with the juice for there to
be good extraction of colour and tannins. Also, acetic bacteria
thrive in such a warm, moist environment, risking spoilage of the
juice.
Consequently, during the process, the juice is drawn out from near
the bottom of the vat and pumped up and sprayed over the cap to
submerge it. This process, known as remontage, has the additional
benefit of aerating the must, which helps to boost the yeast colonies.
This technique of pigeage, simply punching down the cap, is used
for some varieties, particularly Pinot Noir which needs a very gentle
extraction process. Although vats can now be fitted with mechanical
pigeage equipment, in many wineries submerging the cap is done by
hand with wooden paddles, sticks, or even the feet of the cellar staff
precariously suspended over the fermentation vats.
9.4 Maceration
Depending on the style required, the wine may be left to soak
with the skins after completion of the alcoholic fermentation, until