Term for mostly aromatic and fragrant compounds that are similar to alcohols. They belong to the organic acids with low acidity. Besides simple phenols, there are also many phenolic compounds that are also contained in oak wood, such as lignin. They are also found as a component of the skins, seeds and stems of grapes, whereby the content in red wine grapes is significantly higher than in white wine grapes. However, the finest, most aromatic and desirable phenolic compounds are found in the berry skins, those from the grape seeds are rather undesirable. The phenols are responsible for the characteristic astringent taste impression in red wines.