Pietra

Pietra, which means "stone" in Italian and is also known as "A biera corsa", is a brand of beer from the Mediterranean French island of Corsica. The Pietra Brewery opened in 1996. The name "Pietra" comes from Pietraserena, the Corsican home village of the brewery’s founder. Pietra beer is a 6% ABV amber beer brewed from a blend of malt and chestnut flour. Chestnuts have long been used in Corsica as a cereal, but it took many years of research to validate the qualities of chestnut flour. The high fermentability of chestnuts helps maintain the beer's head and contributes to Pietra beer's golden color.

Source: Wikipedia