You have a nose and so do we. Some have more nose than others. Cyrano de Bergerac, whose prodigious schnoz was a permanent feature (that’s Gerard Depardieu in the role of the celebrated swordsman and poet, above) is a famous case study. Pinocchio, whose wooden nose went to great lengths only episodically is another. Wine also has a nose — at least that’s how we often refer to the aromatic profile it presents to us. Both kinds of noses prove to be frightfully complicated things once you begin to investigate.
A number of recent books endeavour to explain just how one or the other goes about its business. In I Taste Red, author and wine blogger Jamie Goode has a go at explaining both. A former science journalist with a PhD in plant biology, Goode may be uniquely suited to the task. He’s readable, but doesn’t soft-peddle the technical bits. One of the things I learned from it is that wine is now thought to have at least three categories of chemical components that make it present as it does.
The first is a set of compounds common to all wine, which together produce a kind of Generic Wine Aroma. Arrestingly, only one of these is present in grapes – the remainder being generated by the activity of yeasts in fermentation (let’s hear it for the wee, industrious creatures).
A second category is comprised of naturally-occurring chemicals that make a collective contribution to the aromatic signature , but which exist in such minute concentrations as to be individually unparseable. A third group, the headliners, consists of the aptly named impact compounds, responsible for the obvious — often flamboyant — aromas we have come to associate with wine from particular varietals.
Impact compounds are powerful molecular structures beloved of professional tasters and amateurs alike, since they permit us, having inhaled a snootful, to opine on the composition and provenance of what’s in the glass. At a molecular level, they are identical to the aroma compounds we find in commonly-encountered organic stuff — flowers, herbs, leaves, fruits, roots, et cetera.
They are legion, and their polysyllabic nomenclature can be sleep-inducing. To cite just a few examples, it’s an abundance of monoterpenes with their seductive floral-spice notes signal Muscat; methoxypyrazines that impresses Cabernet Franc with its idiopathic green herb/Bell pepper stamp. That glass of Sauvignon Blanc before you likely owes its trademark scents of grapefruit, gooseberry (and sometimes cat pee) to healthy doses of polyfunctional thiols. Whew.
It’s marvelous that science is able to explain all this. But there’s a downside. Not content to let terpenes be terpenes, technically inclined winemakers have ways of ramping up these naturally-occurring aromatic flourishes. They may do this by planting vine clones developed specifically to exhibit elevated levels of impact compounds, by employing cultured yeasts that amplify their effects and by fermenting at very low temperatures – a technique aimed at capturing every last volatile scent molecule for the bottle.
The result may be cartoonishly exaggerated scent profiles, even when the base varietal itself (like Chardonnay) isn’t particularly gifted in the aromatics department.
At this point, it’s tempting to posit what we might call the Pinocchio Rule: The less honest the wine, the bigger the nose. Or perhaps a corollary: The bigger the nose, the less honest the wine.
But one needn’t go quite so far. Let’s just say that in the search for more natural and well-proportioned wine, the nose not only knows, it tells.