Base Wine & Blend

Each year's harvest tastes different, yet a bottle of Moët should always taste like Moët. That's what assemblage is for: the cellar master tastes the still base wines individually and blends them into the final cuvée. For the Brut Impérial, Moët & Chandon cites over 150 different wines; Pol Roger speaks of around 30 for its Brut Réserve.

The second lever is reserve wines. A portion of each harvest is set aside and added to the blend in later years. For Moët's Impérial, this share is, according to the house, 20 to 30 percent. Reserve wines balance out lean and bountiful years and bring a maturity that a young wine doesn't yet have.

Behind this lies the question of what distinguishes a vintage Champagne from a non-vintage one. The non-vintage Champagne, known as NV, is the house's flagship and is meant to taste the same every year. A vintage Champagne, the Millésime, comes instead from grapes of a single year, and that year appears on the cork.

A house isn't allowed to bottle its entire harvest as vintage wine. Under the appellation's rules, a maximum of 80 percent of a producer's annual volume may be released as vintage wine, meaning at least a fifth must be set aside for reserves. Dom Pérignon is released exclusively as a vintage, and only in years the house deems good enough.

The color of the base wine is also a key decision point. Blanc de Blancs is made solely from white Chardonnay grapes, while Blanc de Noirs comes from dark-skinned varieties pressed to produce a white wine. For rosé, Champagne rules allow blending white and red wine before the second fermentation. For still wine, this is forbidden within the EU.