The wines of the Douro, cultivated in an inhospitable climate under a scorching sun, with their low acidity and high residual sugar levels, were always difficult to transport. It was for this reason that the region invented fortification, a process which involves adding brandy to the wine before fermentation is complete, providing the Port with its distinctive alcohol-sugar balance, together with a remarkable potential for ageing. In addition, the process requires the rapid and energetic extraction of tannin…