The appellation Champagne applies only to the wines produced according to the long established traditions in the champagne region of France and is the key to differentiating Champagne from sparkling wines. These rules cover all stages of the wine's development, from vineyard cultivation to final bottling. Since 1927, when the vineyards of Champagne were legally defined only three grape varieties have been allowed in the production of Champagne: Chardonnay,Pinot Noir and Pinot Meunier. More recently, measures have been taken to lengthen the minimum ageing time to fifteen months for non-vintage Champagne and to three years for vintage wines.