The Rare Barrel is a sour ale brewery founded in 2013 and based in Berkeley, California. From its early days, the brewery carved out a distinctive niche in the American craft beer landscape by dedicating itself entirely to barrel-aged sour ales — a bold and focused approach that quickly set it apart from more broadly styled craft producers. Over the years, The Rare Barrel grew to become one of the country's foremost producers of sour beer, earning recognition at events such as the San Francisco Beer Week Opening Gala. The brewery's portfolio centres exclusively on barrel-aged sour ales, with a particular emphasis on fruit-infused golden sours, red sours, and experimental styles. This singular dedication to wild and mixed-fermentation brewing gives The Rare Barrel a clear signature: complex, tart, and often fruit-driven beers that reward patient drinkers and seasoned sour beer enthusiasts alike. The use of barrels and unconventional fermentation processes is central to every beer in the range. The Rare Barrel built a loyal following through its Berkeley taproom, which served as a gathering place for sour beer lovers in the Bay Area for nearly a decade. The brand and facility were subsequently acquired by another brewer, ensuring the continuation of The Rare Barrel's legacy in the world of American sour ales.