Can there be white Meritage wines?

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Dear Dr. Vinny,
Can there be white Meritages?
—Thomas K., Northbrook, Ill.
Dear Thomas,
Yes. “Meritage” (which rhymes with “heritage,” by the way, rather than being pronounced with a French accent) is a trademarked name for registered American wines that are blended from Bordeaux grape varieties, and these Meritage wines can be either red or white.
White Meritage wines are based on Sauvignon Blanc, Sémillon and Muscadelle. To qualify, a white must be a blend of at least two of these grapes, with no one grape making up more than 90 percent of the blend, and it can’t include any other grape variety. The rules for a red Meritage are basically the same, but include the grape varieties of Cabernet Sauvignon, Cabernet Franc, Malbec, Merlot, Petit Verdot and the rarer St.-Macaire, Gros Verdot and Carmenère.
—Dr. Vinny