Lambic is a Belgian beer spontaneously fermented with wild yeasts and bacteria from the environment. It is typically aged in oak barrels for months or years. The flavor is sour, funky, and complex, often blended into gueuze or fruited with cherries (kriek) or raspberries (framboise). Lambic is one of the most unique beer styles in the world. Its artisanal production is highly respected among brewers.