Large group of mostly organic hydrocarbon compounds, but sometimes also oxygen compounds, which are the main component of essential oils. These colourless aromatic substances also occur in the form of aldehydes, ketones and alcohols in numerous oils, balsams and vegetable resins. Terpene derivatives are for example camphor, citral, linalool, menthol, nerol (geraniol), pinene and phytol. Carotenoids (a large group of dyes found in the animal and plant kingdom) also belong to the terpenes. Terpenes are present in the grapes in free form, or are also formed in bound form during vinification.
They give the grapes or the wine made from them a characteristic and easily recognisable aroma (primary aroma). They are particularly pronounced with 1 to 4 mg/l in Muscat and Traminer varieties (especially Gewürztraminer) and, in smaller quantities, in Riesling and Sauvignon Blanc. Terpenes are also found in oak wood of particularly American origin. The typical aroma is often described in a wine response with the terms balsamic, flowery(roses) or spicy.