Are barrels important for the winemaker? Oh, yes! None of today’s masterpieces would have been created without the use of barrels.
History has it that…
Thanks to the Celts, it was invented somewhere around the 3rd – 2nd c. B.C. and there came Her Majesty the Barrel!
By the end of antiquity and during the Middle Ages the barrel had gradually become the main wine vessel in Europe. Initially it was preferred because it was more convenient in transporting liquids but as time passed people realized that wines stored in barrels tend to develop and their flavours would change and refi ne.
All sorts of vessels are used in contemporary winemaking but the oak barrel is still very common and that will hardly ever change. No other material is capable of doing what this precious vessel does for the winemakers. There is evidence that chestnut, acacia and Macedonian pine were also used but today this is rather exotic although each producer tries to show originality and a unique style.
Oak is indispensable!
It is valued for its mechanical properties – durability and flexibility, but mostly for its specific chemical qualities and fine structure that facilitates the positive ”breathing“ of the wine. The most important substances that the wine extracts from oak are the phenolic compounds (tannins), of which vanillin has the strongest influence on the fl avour (also referred to as methyl vanillin is an organic compound with a vanilla flavour).
Which one is better?
The quality of the oak depends to a large extent on the soils and climate. The poorer soils in drier regions yield a higher quality material and vice versa. Only trees that grow in forests, not isolated trees, are selected. They have straight trunks and a fine porous structure. Two main oak species are used in Europe – the Quercus robur and the Quercus sessilis. The white oak - Quercus alba is appreciated mostly in America.
In France the oak from the forests in Limousin, Troncais and Allier is considered the best. The best oak forests in Bulgaria are in Northern Stara Planina, Strandja and the Rhodopi Mountain.
Before it reaches the workshop timber undergoes complex preparation. It is first cut into planks in a specific way (only along the radius) to minimize its permeability. Then the planks are stored in an open and ventilated area where they are left to dry for 2-3 years.
French or American? What about Bulgarian?
Two types of barrels with specific flavor profiles have a permanent place in nowadays winemaking – French and American. The former gives finer and more delicate notes to the flavour, while the latter has more eloquent touches of vanilla and spicy.
Bulgarian oak is also considered among the best, not only in Bulgaria. Quality depends on the speed at which the tree grows – if it is fast the timber has wide circles with low density and, respectively, lower quality. That is why higher class winemakers avoid American oak, which is among the fastest growing. Our oak grows slowly and combined with our specific climate has thick circles and high density. In terms of quality it stands along the best of French oak (unfortunately only a small part of the production remains in Bulgaria).
A specifi cally delicate moment is the toasting (charring) of the staves. This operation changes the chemical composition of the wood thus affecting the flavor of the wine. There are three main levels of toasting - Light, Medium and Heavy. The light toasting for approximately 90 min. at 170-180 °C gives fruity, fresh notes, the medium toasting - between 90 and 120 min. at 190-210 °C - gives flavours of cinnamon while at the highest temperature – 220-230 °C for 90 min. (heavy toast), the flavours of leather, tobacco come out, suited for full-bodied and elegant wines.
Or in other words – when lightly toasted barrels are used the flavours of the wood integrate less into the wine. With medium toasting the process is more vividly expressed. This is when the touches of vanilla, roast and spices become dominant. With heavy toasting some of these flavours become too aggressive and suppress varietal characteristics of the wine.
Barrel volume is of enormous importance. Some wine producers use larger barrels but most prefer smaller vessels. Each type has its advantages and disadvantages. In the smaller vessels the maturation goes faster but liquids evaporate more intensively through the staves.
Aging in bigger barrels is slower but more difficult to control. Standard capacities of the barrels vary from 200 to 400 l (205 l in Champagne, 225 l - barrique in Bordeaux, 228 l in Burgundy and 300-400 l in Australia and New Zealand). The lifespan of a barrel is three to four fi lling cycles.
The barrel for the winemaker is what the palette is for the painter!