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It shouldn’t come as a surprise that the alcohol levels in wine have increased in recent years. Cabernets made in California in the 1970s contained around 12 per cent alcohol, while most made today are 14 per cent or higher. Red wines produced in Bordeaux, Tuscany and Piedmont have experienced similar increases according to a new report that surveyed alcohol levels in so-called fine wines over the past 30 years.
The results from the study conducted by Liv-ex, a wine trading company based in London, England, detail how wines made in Bordeaux, Tuscany, Piedmont and California had higher alcohol levels on average in the decade between 2010 and 2019 than they did in the 1990s.
When it comes to wine, it’s impossible to generalize as different winemakers in the same region might embrace completely different approaches. There are a range of stylistic decisions made by individual winemakers in the vineyard and in the cellar that combine to determine the quality and style of the finished wine. But the tendency for riper and more powerful wines continues for most of the premium estate wineries working in France and Italy. (Burgundy is one region where there’s only been a slight increase over time.)
Climate change is the biggest culprit for creeping alcohol levels. Higher temperatures make for riper grapes, with more sugar to convert into alcohol. Taking advantage of warmer temperatures, winemakers often aim to pick riper grapes by letting the fruit hang on the vine longer to intensify the sugar content in the berries. The decision when to harvest the grapes and which yeast strains to use for fermentation also play a significant role. Some yeast strains are more efficient in converting grape sugars into alcohol.
In warmer regions, grape growers and winemakers often explain they cannot simply pick the grapes earlier as the flavours in the berries develop at a slower rate than the accumulation of sugar. If they harvest Cabernet Sauvignon grapes to achieve a desired alcohol level, they might have a tart wine that tastes more like jalapeno or green peppers than cherries or berries.
Wines with higher alcohol levels tend to be rounder and richer in texture, with increased depth of flavour and concentrated character, and often appear sweeter than lower-alcohol equivalents. They are often rewarded with higher scores from critics and wine judges, which is a significant commercial consideration for wineries to consider.
Typically, the hotter the growing season, the higher the alcohol level of the finished wine. However, many decisions in grape growing and winemaking practices can contribute to more – or less – alcohol in the finished wine. For instance, wineries in Australia and California can use reverse osmosis or spinning cone column devices to lower alcohol levels by small increments to make for more balanced wines without harming the flavour.
Liv-ex started to record the reported alcohol levels of wines traded on its website last year and has reportedly gathered data for 35,000 wines so far. In most countries, the reported alcohol level on a label has a margin of error, ranging from .5 per cent to 1.5 per cent, which suggests the real number can often be higher than the reported figures.