http://www.nytimes.com/2013/12/11/d...nes-that-leave-the-sweetness-behind.html?_r=0
Technically speaking, brut Champagnes can range up to 12 grams of residual sugar per liter. Thirty years ago, most brut Champagnes sold in the United States were at the higher end of this range. Whatever lip service Americans paid to dry wine, they preferred a sweet roundness in their Champagnes. For years, in fact, one of the most popular Champagnes sold in the United States, Moët White Star, was not even a brut but a sweeter extra dry.
But as Americans became more accustomed to drinking wine, they began to prefer dryer styles, as did many people around the world. For years now, mass-market Champagne producers have been reducing the sweetness levels of their wines. In 2012, Moët stopped selling White Star in the United States, replacing it as its flagship Champagne with Impérial, a brut.