- Definition:flavour compounds
"The positive description of the aroma components that derive from the grape. The various types of aromas, ranging from floral, fruity, spicy and so on, are listed in the aroma wheel. Both the bouquet in the nose and the retronasal aroma perception at the back of the throat, often described in English as the flavour.
We sub-divide the aromas into three categories, the primary, secondary and tertiary aromas or bouquet. Primary aromas refer to the fruit flavour components found in the grape, and which upon tasting, are recognisable with aromas present in the finished wine. We speak of wine-like or grapey aromas, and often you can recognise the character of the grape variety from a particular scent of berries, fruit, petals or flower, for example the intense rose petal aroma in Traminer. The secondary aromas come from the winery, and are aromatic components that derive from grape handling, fermentation and the maturation of the wine. You can even refer to the smell of fermentation, or detect wine faults (such as too much sulphur dioxide) yet the more desirable aromas include roasting or toasting and vanilla from oak barrel aging. The tertiary aromas are those that develop with bottle aging, a typical example being the development of the petrol note with maturing Riesling. Again, wine faults may also be included, the most common being cork taint".