Why has the alcohol per cent increased in recent years used 12 to 12.5% now 13.5% to 14% and in sum cases 15%?
Answer From Expert Roger Bohmrich MW
The alcohol content of table wine is directly related to the sugars in the grapes. For the majority of familiar wines except for sweet or off-dry types, to name one exception, fermentation transforms all but a trace of the sugars in the fruit into alcohol (I'm simplifying a complex process). It is true that alcohol levels of wines have increased in many parts of the world over the past 10 to 15 years. Grapes are simply riper today - in terms of both sugar and phenolics - than was the case in the past. In traditional European regions, clones of grapevines are generally healthier and more productive, producing more reliably mature grapes every vintage.There is as well a more sophisticated understanding today of how to manage a vineyard to achieve the desired state of ripeness suited to a wine style. It may be a winemaker's choice to delay harvesting so as to push fruit ripeness to the limit; these vintners aim for rich, powerful wines. Last, and of considerable importance, there is a well-documented warming trend in many parts of the global vineyard. Although patterns differ according to location, average temperatures are higher in many wine regions than in earlier decades, and the entire cycle of the vine is more advanced. If you want to read more about the effect of climate change on viticulture, you can look up the articles and research of climatologist Greg Jones of Southern Oregon University.While there are many forces to consider, warmer temperatures essentially translate to riper grapes and more alcohol in wine.
