As a result of its origins, wine is a living product that goes through periods of youth, maturity and aging and, naturally, is subject to changes. For this reason, it does not always have the same composition. The nature of the soil, climate, grape varieties, farming methods and many other factors can cause appreciable differences in each wine and originate products with similar characteristics.
The wine regions in Portugal follow a cataloguing in three possible types: DOC, IPR and Regional Wines:
D.O.C. (Denomination of Controlled Origin)
There are 19 currently, which include names like Port Wine and "Vinho Verde", the most famous and oldest wine-producing regions, or DOC Alentejo and Lourinhã, the latest being the only one of spirit wine.
D.O.C. regions are geographically bounded and subject to a set of rules enshrined in legislation, such as soil characteristics, recommended and authorized varieties, winemaking practices, alcohol content, aging time, etc. D.O.C. Wines can and should use the acronym D.O.C. or quality wines acronym on their bottles as a seal of assurance and cataloguing information.
I. P. R. (Indication of Regulated Provenance)
The regions belonging to this category are in a transitional phase, where the aim is to achieve D.O.C. category, which can happen after a minimum of 5 years if there is the growing of quality wine produced and the vineyard where it is produced.
Although regional wines are not D.O.C. wines, they are of high quality. In some of these cases it happens that a DOC region can produce regional wine by simply not observing one of the rules that define the region as D.O.C., such as the varieties used, the proportions in which they are used or the type of bottle used.
There are table wines that are made up of lots or selections of wines from various regions, and therefore not a geographical demarcation. This type of wine can not mention on their bottles the year of production, the grape varieties used, its aging, etc..
Choosing the wine
In order to choose a quality wine, or acquire a specific taste in wine selection, it should be noted that certain aspects of selection and reference points on wine, such as the vintage of the wine (the same wine usually has quality changes, sometimes substantial, depending on the year of harvest, and therefore one of the key factors of selection), the varieties that make up the wine (if varieties are authorized or recommended by that D.O.C.), its type (White, Red, Spirit wine, etc..), or the alcoholic content. All these aspects appear normally referenced to the benefit of the buyer in the label and back label of the bottle, this being the main wine buyers guide.