Storing wine in barrel

Numerous constituents are transferred from the wood to the wine; through, also, the slow and gradual micro-oxygenation of the wine constituents, the phenomenon possible thanks to the natural porosity of the wood. Between container and content then establish various physico-chemical interactions that result in substantial changes, on both sides, with an exchange totally natural. While staying in the barrel, the wood gives the wine different aromatic substances that affect the taste and then the smell of the wine. Among these we should mention the vanilla extract, responsible for the most typical aromas in the wine aged in wood: vanilla. Also are sold other aromatic substances, depending on the type of wood and the type of processing of the cask, which confer generally to wine aromas of spices.

During this process, the wood also yields also polyphenolic compounds, generally defined tannins that give the wine more structure and also typical color. The effects of the barrel on the color of the wine is more clearly visible in white wines which are accentuated hues pale yellow and even golden yellow. It should be recalled that the input and the influence of these factors is regulated by the size of the cask, from its roasting, the age of the barrel and by the time elapsed from the wine inside. The greater the size of the cask and the lower the ratio of contact surface / volume of wine, therefore the lower the influence of the elements transferred from wood to wine.

Conversely, the smaller the size of the barrel, and then lower the volume of the wine, and the greater the impact on the organoleptic qualities - aroma and flavor - of wine. The use of barrels or barrels must be performed by qualified technicians to identify the most appropriate parameters (surface / volume ratio, aging time) considering each wine in each vintage, and identifying the best solutions objectively based on experience, research and experimentation. Often, in order to standardize the product, the cuts are made with wines from barrels of different ages and, as regards the times of aging, it is called months, in the case of small containers, and a few years for red wines important, aged in large oak barrels.

In France and Germany, in particular, but the practice is spreading in Italy, the barrels are used for fermentation of white wines, in order to get a good taste "woody" because balanced tannins. Also the barrel is used to the classic passage, lasting a few months, that wines, both white and red, not aging, are subject to aspire to the highest standards. The barrels instead of large capacity are normally used for the aging of red wines. In fact, with the slow phenomena of micro-oxygenation that the tannins in these wines can evolve, damping youthful edginess to reach the final characteristics of aromatic richness and harmony. Even liqueur wines and dessert, are stored in wooden barrels to benefit the important role of controlled release of oxygen. In addition to wine, a wide range of drinks is aged in wooden casks as the spirits (brandy, cognac, whiskey ...) where the contributions of wood are needed both for the color to the tastes provided, and vinegars, both common that balsam: the latter, especially, require barrel aging for 12 years. In these cases, the species used are not limited to oak but range from chestnut to cherry or almond for distillate with juniper and mulberry for vinegar.

During the period of permanence of the wine in the barrel occur, furthermore, other important processes that will be fundamental and determinant for the quality of the final product. Wood is a porous material and therefore allows the passage of oxygen and liquids. Both water and the ethyl alcohol through the slats of the cask and reach the outside thereby determining a concentration of the wine; this factor is of extreme importance for the development and maturation of the same. The water, which in wine represents on average for 87% and which has smaller molecules than those of ethyl alcohol, moves more easily and more quickly through the wood and reaches, first, the outside of the barrel.

Outside of the drum as a function of the water evaporates in the local storage of barrels. In conditions of relatively low humidity, water evaporates more rapidly alcohol, with the result of a concentration of the components of the wine which does slightly increase the alcohol content, more or less than a few tenths of a degree. The effects change in the case where the barrels are kept in rooms with relatively high humidity. In this case, the evaporation of alcohol will be in relation to the amount of evaporated water, therefore there may be also a slight lowering of the degree of alcohol. The evaporation of water and alcohol is also conditioned by the thickness of the staves, by temperature changes and by air currents circulating in the cellar.

The evaporation of water and alcohol favors the concentration of wine, but also causes the decrease of the level of the same inside the cask, leaving a "dangerous" empty space that will be occupied by air, then by oxygen. For this reason, the barrels are frequently filled with the same wine in order to keep always full and free of air that would result in a clear and harmful oxidation of the wine. Despite carrying out the periodic topping with the aim of eliminating air, oxygen still unable to enter into the barrel through the pores of the wood. This small amount of oxygen is actually very positive for the purposes of the maturation and development of the wine and represents one of the particular responsible for the evolution that the wine undergoes in time. Oxygen supports the combination of the various elements that make up the wine giving thus a more rounded and soft.