Jolly Pumpkin Artisan Ales is craft brewery in Dexter, Michigan founded by Ron Jeffries in 2004. Jolly Pumpkin produces a variety of unfiltered and unpasturized "rustic country beers".
 
They age their beers in wine barrels which contain naturally occurring microbiological cultures including brettanomyces. These cultures produce a complex flavor profile in beer which includes flavors described as leathery, earthy, wild, funky, or even "sweaty horse hair character", and which may approximate how some beer tasted before the advent of pasteurization and industrialization. This style of beer has been described as farmhouse ales, or American Wild Ale.
 
The Oro de Calabaza won the 2004 Gold and the 2005 Bronze Medal in in the Belgian- and French-style ale category at the Great American Beer Festival. Their Bam Bière was named the 21st best beer in America by Men's Journal.
 
Year-round beers
Oro de Calabaza
La Roja
Bam Bière
Calabaza Blanca
E.S. Bam

Seasonal beers
Madrugada Obscura
Bière de Mars
Luciernaga
Weizen Bam Bière
Bam Noire
Fuego del Otono
Maracaibo Especial
Noel de Calabaza