Port Wine
There is always more to know about the huge world of wine. We found a book densely packed with wine knowledge and wanted to share this great excerpt about port wine (a sweet wine, often served for dessert). The book is called "Wine: A Basic Course."
Title: Wine: A Basic Course Author: Tom Forrest Excerpt: |
Port
One of the great fortified wines of the world, Port is made in many styles, but is rarely copied to the same level of quality as, say, red Bordeaux. To a certain extent, this wine came about by accident. The Methuen Treaty of 1703 was a trade treaty signed between the British and Portuguese governments, and it included sending wines to England. It was common practice to add some brandy to wines that were being transported a fair distance in those days to stabilize and preserve the wine. Soon, the brandy was being added during fermentation to kill the yeasts and leave some residual sweetness, so beginning the development of the Port wines that we enjoy today.
The important factor in making Port is the rapid extraction of color from the grapes. The early fortification results in residual or unfermented sugar being left in the wine, and, because the wine is then placed in barrels, it has to be separated from the skins.
So maximum and efficient extraction of the color from the skins is essential. This is one of the reasons for the large number of grapes permitted in the production of Port. Some have thick skins and one or two are members of that small group of grapes that have a colored juice.
Traditionally, treading the grapes by foot helped this process. The foot is an almost perfect pressing implement. It is hard enough to split the grapes and gently squeeze the skins to extract the color and tannin required, without splitting the seeds and releasing their bitter oils into the wine. After a hard day in the vineyard, the pickers would jump into the shallow troughs or lagars (with clean feet, one hopes!), have a party and tread the grapes. Nowadays, costs mean that this practice is only used on the top quality vintage Ports of some producers.
Over the years, other methods have been developed to extract the color. The most commonly used method is the "autovinifier." This is a sealed vat, which uses the pressure of the carbon dioxide produced during the fermentation process to pump the fermenting juice over the "cap" of skins that floats on the surface of the juice.
Recent research, however, has led to the development of a mechanical process, which replicates the human treading process, the aim of which is to make a wine with the intensity of color and structure, aroma and elegance, and concentration of phenolics, that you find in vintage Ports, without the costs involved in treading by foot. To date, the producers have, by comparative experimentation, developed a piston process, the Port Toes, that is used to produce all styles of Port with the exception of vintage Port. It has been found that, while the machine cannot equal humans yet, it is a great improvement on the autovinifier.
In the spring, once the wine has settled down after the shock of fortification, it is transported down the Douro valley.
- from "Wine: A Basic Course," by Tom Forrest
The important factor in making Port is the rapid extraction of color from the grapes. The early fortification results in residual or unfermented sugar being left in the wine, and, because the wine is then placed in barrels, it has to be separated from the skins.
So maximum and efficient extraction of the color from the skins is essential. This is one of the reasons for the large number of grapes permitted in the production of Port. Some have thick skins and one or two are members of that small group of grapes that have a colored juice.
Traditionally, treading the grapes by foot helped this process. The foot is an almost perfect pressing implement. It is hard enough to split the grapes and gently squeeze the skins to extract the color and tannin required, without splitting the seeds and releasing their bitter oils into the wine. After a hard day in the vineyard, the pickers would jump into the shallow troughs or lagars (with clean feet, one hopes!), have a party and tread the grapes. Nowadays, costs mean that this practice is only used on the top quality vintage Ports of some producers.
Over the years, other methods have been developed to extract the color. The most commonly used method is the "autovinifier." This is a sealed vat, which uses the pressure of the carbon dioxide produced during the fermentation process to pump the fermenting juice over the "cap" of skins that floats on the surface of the juice.
Recent research, however, has led to the development of a mechanical process, which replicates the human treading process, the aim of which is to make a wine with the intensity of color and structure, aroma and elegance, and concentration of phenolics, that you find in vintage Ports, without the costs involved in treading by foot. To date, the producers have, by comparative experimentation, developed a piston process, the Port Toes, that is used to produce all styles of Port with the exception of vintage Port. It has been found that, while the machine cannot equal humans yet, it is a great improvement on the autovinifier.
In the spring, once the wine has settled down after the shock of fortification, it is transported down the Douro valley.
- from "Wine: A Basic Course," by Tom Forrest