Since 1842, when the 270-year-old house of Moët & Chandon began maintaining records, it has produced only 70 vintage Champagnes, each one representing an exemplary harvest. But the two latest releases—Moët & Chandon Grand Vintage 2004 Brut ($60) and Grand Vintage 2004 Rosé ($68)—may be the most spectacular yet. That is partially because, unlike past Grand Vintages, most of which have been aged for up to six years, the 2004 vintages have spent seven years on the lees, allowing one more year to further d…