Whether from a corner shop or the most revered terroir, the glass of red wine in your hand has grown stronger.
While critics have long noted the trend, data from the fine wine market Liv-ex tracks rising alcohol levels over thousands of vintages over 30 years.
During that period, the average alcohol by volume in red wines from California, Piedmont, Tuscany and the Rhone and Rioja regions all rose from less than 14 percent to well above. Riojas rose in strength from an average of 13.1 percent in 1995 to 14.5 percent in 2018.
Climate change has driven the shift, said Tom Gearing, chief executive of fine wine investment group Cult Wines. “The fundamental characteristic is the changing climate. Grapes produce a higher sugar content when it is warmer, which leads to a higher alcohol content.”
Extreme weather conditions can leave their mark on a particular vintage: for example, a severe heat wave in South Australia in 2005 led to an increase in alcohol content.
But another driver has been consumer preferences and winegrowers who adapt to that taste, said Anthony Maxwell, a director at Liv-ex.
Many drinkers in the 1990s preferred “old-school claret” with a lower alcohol content, he said, “but then came the New World wines as an influence, which were riper with a little more sugar . . . Then there was a push from the ‘Robert Parker effect’.
“The wine critic had phenomenal power and influence. He liked riper, more concentrated wines.”
Parker wrote the Wine Advocate newsletter and made a name for himself with early and controversial praise for the 1982 vintage Bordeaux, from a mostly warm, sunny and dry year.
His 100-point scoring system became widely accepted, leading critics to use the term “Parkerization,” as vineyards tweaked their wine in search of higher Parker scores—although the American writer herself always rejected this idea. Still, in the Parker era, mature and robust wines became the norm.
Liv-ex collected data on approximately 17,000 wines, whose alcohol content on the label was originally recorded as part of a process to generate commodity codes for export.
The rise in alcohol content among Bordeaux wines was both steady and pronounced, rising more than a percentage point from the 1990s through the 2010s to about 14 percent.
“At that time there was probably a push in Bordeaux to try and find some more ripeness in the wines,” said Maxwell.
“That combined with global warming”. . . and some vineyards in the south of Bordeaux also felt the influence of the city.” The city of Bordeaux itself generates heat, raising the temperature in the nearby vineyards.
Vintners can influence the ripeness of their grapes by timing the harvest, by manipulating the canopy of the vine, or by the degree of “green harvesting” or by removing extra grapes from a vine.
Capitalization, adding sugar before fermentation, increases alcohol content, while cultured yeast allows more efficient conversion of sugar to alcohol.
While Liv-ex’s data primarily reflects fine wines, experts say the trends are similar in the mass market.
Australian group Accolade Wines, which makes brands like Hardys and Banrock Station, said the alcohol content on the market had “risen marginally over the past few decades”. “This is a global phenomenon,” added Nigel Sneyd, global director of wine and quality at Accolade.
Loire wines and Riojas also showed a steady rise in alcohol, according to Liv-ex; red wines from California, Piedmont, and Tuscany got significantly stronger from the 1990s through the 2000s, but their alcohol content then dropped or retreated.
Levels in white are generally much more stable than in red. “With white wines, the grapes are usually harvested earlier and grown in slightly cooler climates. They naturally contain less alcohol,” says Maxwell.
Similarly, champagne growers pick grapes earlier to maintain acidity, which keeps the alcohol content relatively low.
Sneyd said it was unlikely that the overall alcohol content would continue to rise. “Higher alcohol causes an imbalance in the palate, so any levels that are significantly higher than the current [ones] will need technology to bring them back,” he said.
There has also been some sort of backlash against the decades-long trend for rich reds.
Maxwell links a leveling of alcohol content in some areas, such as Bordeaux’s Saint-Émilion region, with Parker’s retirement – he stepped down as editor-in-chief of his newsletter in 2012, before fully retiring in 2019.
“There was a movement towards – ‘maybe we don’t want these riper and riper wines with higher alcohol content. Let’s go back to picking earlier,’ said Maxwell. “There’s a health corner to this. Nowadays people pay more attention to alcohol.” Accolade says consumers are increasingly looking for wines with little and no alcohol.
And in some regions, especially in more variable European climates, the focus has shifted to mitigating the effects of climate change, using methods such as slower and cooler fermentation, Gearing said.
“Many winemakers are now implementing practices to control alcohol levels and make sure they don’t get too high,” he said.