Once at the wine cellars, grapes are triaged in order to assess their sanitary condition. Once they are weighed and the probable degree of alcohol has been verified using a refractometer (an instrument that measures the sugar content of the grapes), a selection of the grapes is made in accordance with the type of wine that one wishes to obtain. From here, the beginning of the delicate transformation process takes place. The must which results from the pressing is subjected to a fermentation, that may be partial or total, and subsequent fortification.
The fortification process consists in stopping the fermentation with the addition of vinous alcohol at 96% Vol. The interruption of the fermentation is done in accordance with the degree of sweetness one wishes the wine to have. With this process, four types of wine may be obtained: dry, medium dry, medium rich and rich wines.
Once this process is terminated, wines may be subjected to one of the following production processes: “Estufagem - Wine Heating” or “Canteiro - Storage in bottles”.
Once this process is terminated, wines may be subjected to one of the following production processes: «Estufagem» or «Canteiro», two different heating processes.
«Estufagem»
The wine is placed in inox stainless steel vats that are heated via a serpentine method. Hot water, at a temperature between 45 and 50 degrees Celsius, runs through this serpentine system for a period of never less than three months. Once the “estufagem” is completed, the wine is subjected to a period of “estágio” or let rest for at least 90 days in order to acquire the conditions that will make it possible for the oenologist to finish the wine so that it may be placed in a bottle with the required quality guarantee. These wines may never be bottled and commercialised before the 31st October of the second year following the harvesting and are typically batch wines.
«Canteiro»
The wines that are selected to age in Canteiro (this denomination comes from the fact that casks are placed on wooden support beams called canteiros) are aged in casks, usually in the top floors of the wine cellars, where the temperature is higher, for a period of two years. It has a type of oxidative ageing in the cask, making the wine develop unique characteristics of intense and complex aromas. Canteiro wines may only be commercialised once at least three years have elapsed, counting from the 1st January of the year following the harvest.