The humble origins of this intoxicating wine can be traced back to the early 1700’s to a small region of Portugal called the Douro Valley. Is it a coincidence that the word ‘Douro’ means, ‘of gold’? I guess you’ll just have to taste if for yourself and decide!
Port wines are different from other wines in that they are fortified with high-proof grape brandy. Anyone can add brandy to their wine, but this does not necessarily make a port wine. It’s all in the timing. Port wine begins like all other wines. Yeast is added to the juice to start alcoholic fermentation where the tiny yeast fungi will consume the sugar in the grape juice and convert it into equal parts alcohol and carbon dioxide gas. It is during this process that the fortification happens. When the brandy is added, the alcoholic concentration of the fermenting juice is increased instantly. This sudden change in environment stuns the yeast, which cannot continue to ferment the wine now that the alcohol is somewhere in the range of 18-20%. The result of this addition of brandy is an unpalatable wine that is both high in alcohol and high in natural grape sugar that was never fermented. So, when is the right time to add the brandy, you ask? The answer is simple! It depends….
You see, there are hundreds of different strains of yeast, and all of them ferment at different rates. It is the job of the winemaker to monitor the rate at which the yeast are carrying out the fermentation. A simple test is done to the grape juice before the addition of the yeast to determine the starting amount of sugar. Then, after the yeast is added, a close eye must be kept on the amount of sugar left in the juice as the yeast are consuming it. By determining how much sugar has been consumed, we can get an idea of how much alcohol has be made by the yeast, there by deducing how much brandy needs to be added to the juice to reach the alcohol concentration desired by the winemaker. Determining when to do this is the tricky part. It’s all about the taste. If the brandy is added too soon, we will be left with too much sugar making the resulting wine sickening sweet; however, if we add the brandy too late we will be left with a very light style of port that is lacking in sweetness and body. Unfortunately, the yeast are finicky and never ferment at the same rate as previous years. This means that once the yeast is added it’s a waiting game. We wait until just that perfect moment when the addition of the brandy will create that magical port. Unfortunately for this writer, the timing of this addition doesn’t always work with my sleep schedule. There have been a couple of ports in years past that have required fortification in the middle of the night! Ugh…
Once fortification is done, the new port wine is moved to old, oak barrels where it can begin its aging process. It is during this time that the alcohol will start to mellow, and the flavors of the grapes will start to take center stage as they mature into the drink we have all come to know and love. The next time you pop the cork on your favorite port, remember all of the love that went into producing that great bottle of wine!