American readers may be growing weary of European writers complaining of high alcohol in a growing number of California wines, but for us it is a real issue. I drink wine with meals, and I like to drink a reasonable amount. My wife and I usually split a bottle, though her consumption is more modest than mine. Over recent evenings we have been tasting a few young red Bordeaux that I needed to assess, and rather to our surprise we finished each bottle with ease. The wines just slipped down effortlessly.
More often, we struggle to finish the bottle. An Australian Shiraz with 15.5% or a Santa Barbara Pinot Noir weighing in with 14.8% simply defeats us. Either we grow weary of the overbearing 
character of the wine, or we become aware that we are becoming tipsier than either of us wish to be. So we call a halt for the evening.
If the ascending alcohol level in wines from all over the world (California is hardly the sole culprit) were merely the result of global warming, then I would have to shrug and bear it. But it is perfectly clear that it is largely a consequence of human choice. It is wineries and winemakers who beg growers to leave the fruit on the vine until as late as possible in the growing season in search of maximum ‘hangtime.’ The usual explanation is that phenolic maturity–primarily the maturity of the tannin-rich pips–lags behind sugar accumulation, and grapes need to be picked at full phenolic maturity, even if the consequence is wines with very high alcohol.
I don’t buy it. I am an enthusiast for California wines and have been visiting its vineyards for almost thirty years. I recall, and have technical data to prove, that twenty years ago even Napa Cabernets rarely exceeded 13% or 13.5%. Indeed, 12.4% to 12.6% was very common. Last week I sampled a recent vintage of the regular Mondavi Napa Cabernet. It weighed in at 14.5%; in contrast, the 1987 Reserve–no wimp of a wine–had been two entire degrees lower. At the prestigious Staglin winery, there has been a jump in alcohol levels since 1998. There are Staglin admirers who claim the wines have improved in recent years, but I am all-too-aware of that new whack of alcohol hovering around 15%, and prefer many of the wines from before 1998.
Don’t conclude that I am taking a disapprovingly puritanical view of alcohol. My view is quite simple. I don’t care what the numbers say on the label; the only issue for me is whether I am aware of the alcohol itself as I savour a wine. All too often the answer is yes, and that for me diminishes the pleasure of drinking it. There are wines that actually need high sugar levels that will inevitably result in high alcohol. A Châteauneuf-du-Pape below 14.5% would be weedy, and a Sagrantino di Montefalco at 13% would almost certainly taste astringent. Similarly the overt fruitiness of a good Zinfandel seems to carry high alcohol quite effortlessly. I can drink a Dry Creek Zin or a Paso Robles Syrah with 15.5% without a murmur of complaint, because the fruit remains dominant and thus the wine is balanced.
So I am not applying dogma here. I regularly blind-taste flights of wine, so I don’t know as I taste what the alcohol level may be. 
But a California Chardonnay at 15.5% or 16% soon makes its presence felt, and I don’t like that assault of heat and alcohol on the palate. Another consequence of excessive alcohol is that it can be difficult to complete fermentation, leaving an often discernible measure of residual sugar in the wine. With Zinfandel, again, a small amount can be acceptable, but I prefer my Cabernets and Pinots without sugar, please. High alcohol also increases the risk of brettanomyces infection, and a recent tour of the Paso Robles ‘Westside’ wineries revealed both some magnficent wines but also some that clearly exhibit unacceptable levels of brett infection.
Dropping in at the Luna winery in Napa last year, I noted that every single wine in the tasting room was at least 14.6%. Luna, to its credit, is not a producer of cult wines. Its reasonably priced bottles are, I expect, designed to be tasted, bought, and enjoyed by the purchaser quite swiftly. Apart from the fact that in some of the wines the high alcohol was clearly discernible on the palate, it seemed odd that at a time when we are all concerned not only about our personal health but about the dangers of driving with too much alcohol in the blood that we are prepared to accept ever higher levels of alcohol. In Europe, were you to consume a half bottle of new-wave, high-alcohol California wine and have the misfortune to be stopped by our zealous police, you would probably spend the night in jail and be fined heavily.
I don’t recall Napa Cabernet from the 1980s or Bordeaux reds from even further back showing any lack of flavor. Some of the classic Bordeaux vintages, wines that are still drinkable today, had no more than 10.5% or 11%. Some of these historic wines might have had some herbaceous character that today’s fruit-obsessed wine drinkers might find unacceptable. I accept that Bordeaux vintages such as 1972 were quite simply vegetal, and disgustingly so. But a slight herbaceous edge can be attractive, at least to European palates.
In contrast, the super-ripe wines that win such applause today have a very high pH. Without being too technical, the higher the pH the less likely is the wine to be structured with the acidity that will ensure a long and interesting life. Not only does many a California wine these days clock in with 15% alcohol, but its high pH and soupy texture are almost certain indicators that the wine will collapse under its own weight within a few years. That may not matter if the wine is intended to be drunk–and drunk up–on release, but for me part of the pleasure of a wine is enjoying the way it ages. Not for all wines: I drink Zinfandel or Dolcetto young. But I don’t want a Léoville-Barton or a Martha’s Vineyard Cabernet to give its all within a year of bottling. Its evolution, its acquisition of secondary aromas and flavours are all part of the pleasure.
The tide is turning in Europe. Wine drinkers don’t enjoy being hammered with alcohol as they finish a glass of wine. At many London wine bars, three large glasses of wine amount to an entire bottle. I don’t know about you, but after an entire bottle of wine at 15% I am starting to feel distinctly queasy. The British retailing chain Marks & Spencer has recently announced that it will be actively seeking out wines with lower alcohol, 12.5% being about right. This surely is a corrective trend to be welcomed.
Stephen Brook is a contributing editor to Decanter, and over the past fifteen years he has won major awards for wine writing in Britain, the U.S., and Australia. His books on wine include Liquid Gold: Dessert Wines of the World; Sauternes; Pauillac; A Century of Wine; The Wines of California; Bordeaux: People, Power and Politics; and The Wines of Germany.