Take two growing seasons: 1961 and 2010. Take two red wines, the kind that most of us only get to dream about, from those vintages: Château Latour and Penfolds Grange. Compare. Latour 2010 (considered one of the greatest Médoc wines of the 21st century) contains 14.4% alcohol by volume (abv); Grange 2010 (5 stars and 99 points from The Vintage Journal) has 14.5%. Latour 1961 (lavished with perfect scores aplenty) has… 12.3%; Grange 1961 is at 12.7%. Grange ’62, regarded as a finer wine than the ’61, is even lower at just 12.2%.
Stranger still, written tasting notes suggest similarly styled wines. ‘Rich and voluminous,’ reads The Vintage Journal tasting note on the 12.2% Grange ’62, while Latour ’61 was (as noted by Robert Parker in June 2000) ‘Port-like, with an unctuous texture… full-bodied, voluptuous’. Michael Broadbent called it (in 1999) a ‘mammoth wine’. Rich and voluminous – at 12.2%! Voluptuous and mammoth – at 12.3%! Grange 2010, less surprisingly, is described as ‘a powerhouse’ (James Suckling, 100 points, 2014 note), while Latour 2010 is ‘a liquid skyscraper in the mouth’ (Robert Parker, 100 points, 2013 note).
That grinding gear-change in alcohol level, echoed universally around the wine world, is our subject. Alcohol levels in wine have risen significantly over the last half-century. Why has it happened, how do we feel about it and what are we doing about it?
The factors at play
There are many reasons why alcohol levels have risen so dramatically over recent decades. Anthropogenic climate change (the vineyard consequences of which include, compared to the 1960s, earlier bud break; hotter and shorter growing seasons, ripening under brighter sunlight and during longer day lengths; and earlier harvests) is the one we should take most seriously – since it affects not just wine production but our survival as a species. The largest contributor to global warming is atmospheric carbon dioxide: 317.64ppm in 1961 (according to mean measurements at Mauna Loa Observatory in Hawaii, begun in 1958); 428.55ppm on the day I write this.
There are, though, other wine-specific factors at play. Vine health has improved, meaning that vines perform more efficiently; soil management, pest control, canopy management and yield control optimise quality, which means that musts are richer; selected yeasts convert sugars to alcohol more thoroughly during fermentation.
Consumer preferences (in part based on critics’ scores) have also played a role, notably during the period (1990-2010) of Robert Parker’s critical prominence, when there was a shift towards late harvesting, giving ripe, opulent, powerful and often low-acid wines. Since 2010, the reverse trend has been underway in many regions, with wine-growers increasingly seeking qualities such as tightness, tautness and precision built around earlier harvesting and more prominent acidity levels, sometimes with lower alcohol levels.
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