Olfactory analysis: the Nose

The human nose is sensitive to around 10,000 different odors. (the father of modern oenology) distinguishes ten classes of odors: animal, balsamic, woody, chemical, ethereal, spicy, empyreumatic, floral, fruity, vegetal. The olfactory analysis of wine is a difficult exercise to understand because we must put aromas into words and use our olfactory memory.

It takes place in 2 stages:

• The first step consists of smelling the wine in a tasting glass one-third full and held by the stem to avoid unwanted odors (for example perfume). We call this the “first nose” .
• Taste is felt on the taste buds located on different areas of the tongue: sweet on the tip, salty on the lateral sides, sour on the edges and bitter on the back of the tongue. The sweet flavor is revealed first, then come the sour and salty flavors. The bitterness only appears at the end of the tasting. In addition to these basic flavors, other sensations are detected: freshness (acidity), heat (due to alcohol), astringency (tannins), fizz (CO2), consistency (fat). We will characterize the acidic taste in wines by the following adjectives: flat, hollow, lean, balanced, fresh, nervous, lively, acidulous, green, acerbic, aggressive, acidic, very acidic. The sweet taste of wines comes from residual sugars, glycerols and alcohol. .
• Primary or varietal aromas: they mainly characterize the grape variety used and can be influenced by the climate, the terroir, etc.
• Secondary aromas: they come from winemaking. The alcoholic fermentation of grape juice gives rise to new compounds which complement the primary aromas of the grape. These aromas depend on the nature of the yeast and the temperature at which fermentation is carried out. Malolactic fermentation also brings aromas to the wine, notably buttery and milky notes. .
• Tertiary aromas: they come from the evolution of the wine over time and the terroir. They can be observed after 30 minutes of aeration and in the empty glass. These are the most complex.

The aromas coming from wine defects are also the subject of a family in their own right. We find notes of rancid butter, rubber, cork, rotten egg, dust, sulfur, soap, nail polish, vinegar...

Aging attenuates the original fruity notes but makes them more complex. In vats, the wine will tend to retain its young and fruity character while the oak barrel will produce slow oxidation and transmit the very odorous compounds of the burnt oak from the barrel. Depending on the expertise of the winemaker, this “woody” taste will be more or less harmonious, especially if the aging is done in new barrels. .

Bottling will bring the wine into its reduction phase. This phase will bring aromas of leather, meat, even game to the wine, with notes of mushroom, smoke and roasting. Aging also brings about the marriage of aromas and their harmony.