Vermonster is an American barley wine style beer brewed by the Rock Art Brewery in Morrisville, Vermont. This beer was created by Matt Nadeau, the owner of Rock Art Brewery, in celebration of the brewery's 10th anniversary. The beer was created with the theme of "Tens" in that it contains 10% ABV, 100 International Bitterness Units, and 110 pounds of malt per barrel.
The Vermonster is the subject of a legal dispute between Hansen Beverage Company, the maker of Monster Energy drinks, and Rock Art Brewery. On September 14, 2009 Matt Nadeau of Rock Art Brewery received a cease and desist request from Hansen Beverage Company asking that he stop using the Vermonster name and compensate Hansen for its attorney's fees. Nadeau attempted to reach an agreement with Hansen, offering to surrender the rights to the trademark in the energy drink market.