Ludovic Dervin, a native of the Champagne province of France, has made sparkling wines for Mumm Napa for 10 years, with as has as 20 variations at a time in the cellar. He says the Mumm Napa 2007 Napa Valley Blanc de Blancs is sturdy enough to be laid down and enjoyed for another 10 years. At $38 a bottle, it costs about half as much as a comparable Champagne.