Wine Production : Vine to Bottle - Vinum Vine

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tannins soften and acidity levels fall. The choice of maturation
vessel and the period of time depend upon the style of wine to be
produced and quality and cost factors. There are many types of
maturation vessels, including stainless steel vats and wooden barrels.
Some wines which are intended for early drinking, such as inexpensive
or branded wines, need little or no maturation. Stainless steel is an
ideal storage material because it is impermeable to gases such as
oxygen. The wine therefore is stored until required for bottling. Of
course, stainless steel is ideally suited to temperature control and
is used where long-term, oxygen-free storage is required, for example
when inexpensive wines are held prior to being ‘bottled to order’.
Most high quality red wines undergo a period of barrel maturation –
usually somewhere between 9 and 22 months. During the time in
barrels, the wine will undergo a controlled oxygenation and absorb
some oak products, including wood tannins and vanillin. Barrel size
has an effect on the maturation of the wine; the smaller the barrel
the quicker the maturation. Temperature also plays an important
part; the lower the temperature, the slower the maturation. When
the barrels have been filled they will be tapped with a mallet to
dislodge air bubbles, which rise to the surface of the wine, thus
removing oxygen. During the period in barrel the wine will be racked
several times to aid clarification – for example red Bordeaux wines
are normally racked four times during the first year’s maturation,
and perhaps once or twice in the second. Many producers regularly
top up the barrels to replace wine lost to evaporation, but there is
a viewpoint that if the barrels are securely sealed the ullage at the
top is a partial vacuum and topping up may not be beneficial. The
processes of preparing the wine for bottling will be considered later.
CHAPTER 9