The scent of Black Currant Sprouts is very different from that of black currant fruit. Vulgarly, it is also called "cat pee", because it has a pungent smell with vegetal and sulphurous notes.
We are not used to perceiving it every day; one must first have smelled and memorized it to then be able to subsequently recognize it. Precisely because it is an aroma that we do not often perceive, some may associate it with different descriptors. Aside from "cat pee", this aroma can be described as the vegetal notes of boxwood leaf, green broom twig, nettle, green grass and tomato leaf.
In wine, this aroma is delicate and gives elegance and personality to the bouquet. It is an aroma typical of wines obtained from Sauvignon Blanc grapes, and it renders them easily recognizable. This gratifies the wine consumer, who is increasingly attentive to product identification.
Despite being a varietal aroma, (one typical of a particular grape variety), it is not immediately present in grapes or must, but develops only after fermentation, and is therefore also a secondary aroma.
The black currant sprouts aroma is due to a molecule of the "thiol" family: 4 methyl-4mercaptopentan-2one. It has a very low perception threshold for humans and is therefore recognized even when it is present in very low concentrations. The smell of this molecule is not to be confused with that of the methoxy pyrazine molecule, also present in sauvignon grapes, but perceptible only in the less ripe ones, giving hints of green pepper and green leaves.
The black currant sprouts aroma is sought after in Sauvignon Blanc especially when it is light and creates a good balance with the other aromas. In wines, the aroma enhances the sensations of freshness and pungent notes. If the herbaceous notes are too marked, however, they are considered defects related to the poor ripening of the grapes. The aroma is too faint, if not completely absent, in wines produced with overripe grapes and grown in hot climates. Even wine which spends too much time in the bottle can negatively affect the intensity and recognizability of this scent.
In aromatherapy, and in gemmotherapy, the essential oil of currant sprouts is associated with health qualities. For example: it has an anti-inflammatory action (osteoarthritis and rheumatic diseases); helps fight allergies (asthma, hay fever, eczema); helps fight physical and mental fatigue; can have a cleansing action on the liver.