Oak Flavour: Volatile phenols

These too are the product of lignin degradation and are not present in non-toasted wood. They impart a spice-like roasted character, ranging from clove to smokiness. These decrease with seasoning of the oak. The main volatile phenol associated with wood is eugenol (clove-like). Others include guaiacol and 4-methylguaiacol (smoky, charred aromas), which may increase at higher levels of toasting, and 4-vinylguaiacol (reminiscent of carnations).