Green untoasted wood contains trans-2-nonenol, a nasty, planky sawdust aroma that persists in wine for years. To prevent this, oak needs curing outside in weather that will leach tannins and foster subtle microbial transformations. Curing wood is an art, and skill is required to avoid the formation of TCA, the corky aroma. Thus only highly reputable coopers should be entrusted with the production of untoasted chips or barrel heads.
