Oak barrels how crucial are they ?

Traditionally, fortified wines are aged in oak barrels, which are generally seasoned.
The influence of the barrel can be seen as: the origin of the wood and the techniques used for fabrication of the barrel, such as duration and method of drying the wood after cutting, burning intensity, during the assembly and cleaning the barrel before use. The size of the barrel also affects the aging, according to the permeability and more contact with the wood due to the smaller size.

 Aging of old barrel aged Ports in oak barrels, requires a very slow and long process.
The oxygen, which penetrates through the pores of the wood, participates in oxidation reactions, interfering with the aroma and taste of the Port.

The oxidation percentage may vary from 2 % (if the Port is aged at the Cellars in Vila Nova de Gaia) to 6 % per year (if the Port is aged at the Douro Valley, by the smaller and independent producers), depending on the conditions of temperature and humidity of the local.
The alcohol and water do not evaporate at the same rate due to the different degree of volatility. In a humid environment, the alcohol evaporates more easily. In dry enviroments, water evaporates in a higher quantity. A place of more humid aging usually is favorable for obtaining refined Ports.

The strong aroma of alcohol will change to a more subtle aromas with notes of wood, especially vanilla and finally getting a nice complexity.

The quality of the oak it´s also very important – french oak is considered the best one, but the Port barrels can still be made of portuguese  american and hungarian oak or chestnut, but for our Port maturation we only use seasoned french oak, and recently hungarian.

 To make  a first quality barrel you need to wait one century for the tree to grow and 3 years more to smoke and dried it, it´s the reason that normally the flavor of caramel is easy to pick in a tawny ( small amounts of sugar in the oaks cells ), normally when we are thinking about buying a 30y old tawny, a Over 40y old tawny or even a old Colheita ( single year tawny ) and we consider the price expensive, it´s always very important, to keep in mind some of the highest quality factors...
The emblematic coopers room at C. da Silva´s cellar.
Nowadays a slice of C. da Silva´s history...where we keep the old staves, the cooper´s tools, the fire place used to smoke and reduce the thickness of the french oak casks...

C. da Silva´s coopers room

From the thickness of the wood to the braces that mould the staves, one of the secrets of our wines lays in the barrels that store the Port wine, handcrafted by wise cooper masters.

Toasting the french oak casks