There is little agreement on the status of Quadrupel as a beer style. Writer Tim Webb notes that similar beers are called Grand Cru in Belgium even though the idea is derived from the Belgian beer naming convention of that uses numerical values descriptive of the number of prominent ingredients.
In other countries, particularly the United States, quadrupel or quad has become a generic trademark. The term may refer to an especially strong style of dark ale with a spicy, ripe fruit flavor.
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- May. 25, 2007 Philadelphia Daily News, "Belgian taverns debuting all over" Archived 2016-03-04 at the Wayback Machine: "...Obviously that dish demands a hoppy beer (ba-dum), but she opted for a Three Philosophers from New York's Brewery Ommegang, a powerfully satisfying quadrupel flavored with cherry lambic."
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