New woods to make new wines

The current wine market is characterized by certain homogeneity and saturation of products. New techniques and technologies are being sought in order to reduce the cost of the processes and to obtain high quality products that can be distinguished from the rest of wines. Many research groups of oenological microbiology have focused their efforts to achieve these general goals, motivated by an industry that can understand that lower cost products can significantly increase their competitiveness.

Besides, when it comes to wine consumption, there is a particular hedonistic component subject to trends, fashions and opinions. According to researchers, "what people used to like in the nineties, it is not the same than now. Wines of great extraction, high alcohol content and long aging periods have made way for other wines that further respect the primary aromas and varietal fruit through a better integration and balance with volatile wood."

It is important to stand out the high degree of fate and empiricism underlying the link between wine and wood. Have you ever wondered why a barrel of wine has that geometry? The answer is that originally these containers were only used as a container for trade in goods. Wood used to be a tough, affordable and abundant material, and its geometry allowed them a rolling motion of heavyweight (volume) which was linear on rails, and angular on smooth surfaces. Later, the positive influence of the container over the content was perceived and recognized.

This influence is due to the release of certain volatile or not compounds which are already known and completely identified and can enrich the sensorial profile. These compounds make, aromatically speaking, the wines aged in wood more complex. Therefore, from the point of view of the aroma, the barrel is a vehicular object used to enrich the wine in certain wood compounds.

The traditional aging in French or American oak barrels constitutes the only resource to elaborate quality aged wines. It is a long and expensive process; a large volume of wine must be immobilized on winery for varying periods before coming out on the market. The potential aromatic assignment of the barrels is limited. Therefore, its acquisition, maintenance and regular renovation constitute relevant variable expenses in winery. The International Organization of Vine and Wine (OIV) permit the usage of oak and chestnut although the last one is less used.

In this context, the research group of enotecUPM has developed a methodology that aims to exploit the high adsorption potential of volatile compounds that shows the yeast cell-walls used in early stages of its development. These cells are used as a vector that can transfer tertiary aromas coming from aging the wine, precisely controlling this migration.

This methodology is based on the prior aromatization through infusion of a yeast biomass for subsequent release into the wine. This new technique accurately uses other types of wood such as chestnut, cherry and acacia that, after analytical results obtained by techniques of chromatography, these woods show interesting technological skills in certain situations.

This innovative technique provides various interesting alternatives such as lower cost and shorter periods for wine making processes showing similar sensorial profiles to other traditional wines aged in barrels. The physical chemistry research focused on processes involved in aging in wooden barrels aims to optimize this traditional technology and give a reasonable and technically justified usage of the resources.