Minerals and flowers, citrus and caramel, tobacco and jasmine. These and so many other different aromas can be found in a glass of wine, without being actual wine ingredients! How and where do these wine aromas come from?
They are the result of volatile aromatic compounds found in wine and which happen throughout its life, from the vineyard to the moment it reaches our glass. These are esters, acetals, aldehydes, terpenes, ketones, alcohols, lactones, pyrazines, phenols and many volatile organic acids. For example, syrigaldehyde has the property of resembling vanilla. When detecting this substance, we recognise the aroma of vanilla; thus, without adding vanilla to the wine, it is possible to detect vanilla notes in it.
How are aromas formed?
The special character and ‘nose’ of a wine are due to three factors, namely: grape variety, alcoholic fermentation and aging, which in turn create primary, secondary and tertiary aromas.
Primary aromas
Primary aromas differ from grape variety to grape variety and are influenced by the so-called terroir of each region, namely by the cultivation conditions, the soil composition and the climate of the region. In addition, the extraction of the juice and the stay of the must in the barrel contribute to the creation of these aromas. The primary aromas category is where we find terpenes (natural substances derived from plants) which make wine smell of flowers and fruit.
Secondary aromas
Secondary aromas are created during the wine fermentation process and most of the aromas found in wine are because of them. These are the so-called esters (chemical compounds that come from a reaction between acid and alcohol). They provide aromas reminiscent of fruit, mainly pear and banana, and butter-like aromas resulting from malolactic fermentation.
Tertiary aromas
The last category of aromas results from maturation and aging. After bottling the wine, chemical compounds are created due to either the barrel or the stay of the wine in the bottle. Staying in the barrel causes an increase of aldehydes, which is a result of oxidative aging while various substances are extracted from the wood (mainly in new barrels). Typical such aromas are vanilla, oak and spices. On the other hand, a long stay in a bottle can replace the fresh aromas of fruit and flowers with the heavier and more complex aromas of jam, tobacco, leather and soil.
The following characteristics are considered for the aroma of the wine:
• Intensity: wine can be intense, moderate, weak, non-existent.
• Quality: the wine can be of breed, fine, common, coarse.
• The character: can be fruity, floral, vegetal, spicy, animal-like etc.
It is said that more than 500 aromatic ingredients have been identified! To find out as much as possible, all you have to do is practice and take notes for each of your tests!
Chemical Terminology of aromatic ingredients
Methanol = aroma of some apples
Ethanol = the well-known aroma of alcohol that is also reminiscent of certain varieties of apple
Hexanol = smell of freshly cut grass
Starch and Isoamyl alcohol = unpleasant odour, but similar to that of alcohol
Phenethyl alcohol = rose and jasmine aroma
Tyrosol = honey aroma
Linalool = one of the aromatic ingredients of musk, with lemon aroma
A-Ionone = violet aroma
Geraniol = heavy smell of flowers
A-Terpineol = camphor aroma
Octenol = unpleasant smell of mold
Isoamyl acetate = banana and pear aroma
Ethyl capronate = violet and ripe apples aroma
Ethyl Caprylate = less intense fruit aroma, reminiscent of the aroma of Marseille soap
Methyl Savinone ester = tsipouro aroma
Isobutyric acid = aged cheese smell
Butter ether = butter aroma
