Home / Wine Guide / The Back Label
OAK & CLARIFICATION
Of all the species, of all the trees in the world, why oak? This unique wood has Become so synonymous with wine making that we rarely stop to consider how it came to be, or why, considering the advent of stainless steel in winemaking, it should be so enduring.
Words by: ALLISON FREW.
Commercial Manager Scotland.Corney & Barrow London
No two barrels are exactly the same, oak is a product of infinite variety influenced by both its cooperage and its environment.
The relationship began for the most prosaic of reasons. Oak was simply a wood well-suited to barrel making. It is watertight, not too porous, relatively low in flavours and malleable enough to be shaped. The reasons for its continuation involve a little science (chemically oak barrels and stainless steel vats have a completely opposite effect on wine), and of course for the associated flavours and textures which, however subjective and contentious, have become an intrinsic element in all but the lightest and most aromatic of wines. No two barrels are exactly the same. Oak is a product
of infinite variety influenced by both its cooperage and its environment - soil, climate annual weather and assemblage all influence the final product in much the same way that these same elements influence a finished wine. It is this very variability that inspires, challenges - and sometimes confounds the winemaker. Get it right and oak can add eloquence and complexity to a wine's expression of terroir - get it wrong and hard-won nuances of flavour, painstakingly coaxed from the vine over the growing season can be completely muted. Two species of oak are used in winemaking Quercus Alba (American White Oak) and Quercus Sessilis or Robus (European Brown Oak). The quality of American oak barrels has improved enormously over the last few years but it is still French oak that sets the standard - and commands the highest price! Most valued of all is the tightly grained French oak from Nevers, Allier, Tronçais and Vosges (although overall Vosges contributes comparatively little, not because the quality is inferior but rather because some of the trees are full of shrapnel - a legacy of the heavy shelling the area sustained during World War 1). A winemaker may choose either to ferment or mature his wine in oak, or both. The success of the endeavour relies heavily on the winemaker's knowledge, skill and experience to create a balanced, harmonious whole from all the complex elements of both wine and oak. The poor winemaker is faced with an almost bewildering range of choices all of which affect the ultimate flavour, style and quality of the wine.
A winemaker may choose either to ferment or mature his wine in oak, or sometimes both. Wine by its nature, and especially fine wine, resists the industrialisation process and time spent in barrel has other benefits. Stabilisation,
fining and filtration can strip flavours from a wine but some of these processes will happen naturally over time. Although barrels are watertight, they are air - permeable and the resulting slow, measured exposure to oxygen allows for a gentle, natural stabilisation. Unsightly and unwanted particles (the lees) will steadily sink to the bottom of the barrel and the gradually clarifying wine can easily be racked off. Barrel matured red wines are often racked several times and can sometimes be bottled without further need for clarification. For the rest, and especially for white wines a fining agent like bentonite (a type of earth) or albumen (egg white) will be added. These agents bond either physically or chemically with the particles and carry them to the bottom of the barrel. Finally a word of warning - a carefully worded label reference to oak without mention of barrels is generally an indication that the oak has been in the wine, rather than the other way round, and although some worthy results can be achieved with use of oak substitutes (chips or staves), science has not yet been able to fully replicate the subtle nuances, structural complexity or the seamless integration of fruit that results from time spent in a well-made oak barrel. C&B
OAK: THE OPTIONS
American or French: American oak rolls across the wine like a Texan drawl, full, mellow and deep. Rich in tannin with prominent coconut, vanilla and bold spice flavours that some consider a little unsubtle. French oak is
more subdued, less raucous perhaps, but it takes longer to give up its flavours and fully integrate with the wine.American or French: American oak rolls across the wine like a Texan drawl, full, mellow and deep. Rich in tannin with prominent coconut, vanilla and bold spice flavours that some consider a little unsubtle. French oak is more subdued, less raucous perhaps, but it takes longer to give up its flavours and fully integrate with the wine.
Toast: Toast may be light, medium or heavy and the degree of toasting a barrel receives will affect the depth of flavour.
The proportion of new oak: New oak imparts the greatest intensity of flavour and the most wood tannin. 100% new oak or a high proportion of new oak should only be used for wines with the structure and depth of fruit to benefit from extended maturation.
Barrel Size: Barrique (225Ltr), Hogshead (300Ltr) or Puncheon (475 Ltr) - the names are so much more poetic than small, medium or large, but the theory is the same - the smaller the barrel, the greater the oak to wine ratio, and the greater the oak's influence.
Time: Wine may spend anything from a couple of months to several years maturing in cask. Generally reds will mature for longer than whites although its not uncommon for sweet whites like Sauternes to spend up to three years in barrel. The tannins in the oak blend with the tannins in the wine; smoothing the structure, developing suppleness and texture, deepening the flavours and acquiring complexity.
