Side Project Brewing is an American craft brewery based in Saint Louis (Maplewood, Missouri), run by Cory and Karen King. The brewery is renowned for its premium, complex beers fermented in oak barrels, using wild yeasts and spontaneous processes that give each release a rustic and unpredictable character.

Their philosophy relies heavily on local ingredients - such as fruit and native microorganisms - to create unique saison and wild ale styles with a strong sense of terroir. In addition, Side Project experiments with aging in bourbon and other spirit barrels, crafting intensely powerful stouts and barleywines that combine strength and depth with exceptional balance and elegance.

Their work is defined by technical precision, innovation, and dedication to artisanal principles, making them one of the most respected and influential breweries in the world of spontaneous and barrel-aged beers.