Wooden barrels at De Troch, Wambeek. Wooden barrels are a perfect conditioning vessel for fermenting, maturing lambic. The porous wood enables the lambic to breathe and interact with the environment. Barrels made of oak are very much preferred with the type and provenance of the oak playing a big role. French, American, Hungarian, Chinese,…..they each have their characteristics and differences. New, unused barrels are seldom used as the hard, tannin oak taste is not desired in lambic. Second hand barrels, previously used for wine are most common.