Researchers in Belgium have identified an additional inoculation source—the wooden casks or foeders—for producing lambic beers. Traditional lambic beer production takes place through wort inoculation with environmental air and fermentation and maturation in wooden barrels. Up to now, these lambic barrels have only been examined with culture-dependent techniques, missing a part of the microorganisms present. The research is published in the journal Applied and Environmental Microbiology.