Intelligent Life, a new magazine from the publishers of The Economist, has a story about how much of the wine produced in California is "watered back", i.e. diluted with water. Apparently, this is done to keep alcohol content down or to make sure that fermentation occurs if there is too much sugar in the grapes. I'm no wine connoisseur, but I'd be surprised if very many wine drinkers were aware of this.
…French towns and villages are a great deal more picturesque than anything that northern California can offer. Calistoga and Yountville are not exactly Beaune and Châteauneuf-du-Pape. But for the winemaker the obvious difference is the weather: California has longer and warmer sunshine—which means that the fully ripened grapes may well produce a wine with a bit too much alcohol for comfort (too much, also, for the bottom line, since wine and liquor are taxed according to their alcohol level).
One obvious solution would be to pick the grapes earlier, except that that would be at the cost of the "full-bodied" flavour and "big" character of the typical Californian wine. Hence a preference for the other obvious solution: adding water during the fermentation process. At which point, everyone gets a little coy, even a trifle alarmed. Witness the concern of a spokeswoman for California's Wine Institute. "How did you hear about this?" she demanded. "This is a long, long story—it's kind of a stylistic thing."
The state is that great fiction by which everyone tries to live at the expense of everyone else. - Frederic Bastiat