Port wine oxovitisin A, an oxovitisin, a type of pyranoanthocyanin with a 2-pyrone component. Port wine Port wine (also known as vinho do Porto, , Porto, and usually simply port) is a Portuguese fortified wine produced with distilled grape spirits exclusively in the Douro Valley in the northern provinces of Portugal. It is typically a sweet, red wine, often served as a dessert wine, though it also comes in dry, semi-dry, and white varieties. Fortified wines in the style of port are also produced outside Portugal, including in Australia, France, South Africa, Canada, India, Argentina, Spain, and the United States. Under European
Vinho Verde they are usually consumed soon after bottling. A Vinho Verde can also be a sparkling, a Late Harvest or even Brandy. In its early years of production, the slight effervesce of the wine came from malolactic fermentation taking place in the bottle. In winemaking this is usually considered a wine fault but Vinho Verde producers found that consumers liked the slightly fizzy nature. However, the wines had to be packaged in opaque bottles in order to hide the unseemly turbidity and sediment that the "in-bottle MLF" produced. Today, most Vinho Verde producers no longer follow this practice with the slight