The term (grch. for "spice") plays an important role in the evaluation of wine and the way it is addressed. Wine contains many hundreds of aromatic substances, which account for a proportion of 0.8 to 1.2 grams per litre. They can be determined in the laboratory by chromatography. In general, aroma is the scent or, poetically, also called "nose" of a wine. The aroma is thus perceived by smell (nose) and not by taste (palate, tongue) and therefore strictly speaking has nothing to do with taste. In unpressed grapes, most of the aromatic substances are present as glycosides (sugar compounds) and are still tasteless and odourless. This is why they are called aroma precursors. These can be measured in the grapes using the glycosyl-glucose assay.
The aromas go through three stages. The primary aroma (varietal aroma) comprises all the fruity notes that are already present in the berries and are particularly noticeable in the pressed juice. These varietal notes vary according to the grape variety. They are particularly strong and characteristically pronounced in the bouquet varieties. The secondary aroma (fermentation aroma) includes all the odours that arise during vinification. These include the aromas formed during fermentation (some of which disappear again), the yeast odours during yeast settling and the roast aromas during barrique ageing. The tertiary aroma (maturing aroma) comprises all those aromas that are created during bottle maturing. This also includes ester, firn and petroleum clay. Through the interaction of oxygen, acids and alcohol, completely new aroma substances are formed.
This tripartite division of flavours is widely recognised in professional circles. There are, however, different opinions on the term bouquet (also bouquet). It is often understood to mean the overall picture of a wine after bottle ageing, i.e. the primary, secondary and tertiary aromas mentioned above. In some cases, however, the total taste impressions are also included. In Anglo-Saxon literature, however, a distinction is often only made between the two stages of aroma (primary and secondary) and bouquet (tertiary). And in Australia, flavour is only understood to be the typical character of a variety (primary aroma).
There is also the term Arôme de Bouche (retro aroma, mouth aroma, retrogusto and retro odour), which is used specifically in France. This term refers to the aromas that are perceived olfactorically in the nasopharyngeal cavity during exhalation (retronasal). Where the two terms aroma and bouquet differ is therefore not clearly defined and is interpreted differently. In any case, new aromatic substances are created during vinification from the fermentation process onwards. See also under aroma wheel (aroma circle), aroma set, aromatic and flavouring, as well as a list of the ingredients in the wine under total extract.