Cabernet Sauvignon

Identity

Cabernet Sauvignon is one of the most tannic grapes in this encyclopedia, and one of the most recognisable. The reason is morphological: very small, thick-skinned berries, therefore an extreme skin-to-pulp ratio, therefore a great deal of colour, tannin and aroma precursor per litre of juice. A Cabernet Sauvignon is never slight.

It is also a grape that demands heat. It buds thirteen days after Chasselas and ripens in the third period, three to three and a half weeks after it. That very late cycle is both its protection — it sidesteps spring frost — and its risk, because in a cool vintage it stays green and delivers pyrazines.

History and origin

Cabernet Sauvignon was born in Bordeaux, probably in the seventeenth century, from a spontaneous cross between Cabernet Franc and Sauvignon Blanc. The name, long taken for a nurseryman's flourish, turned out to be literally true: a Cabernet descended from a Sauvignon.

The proof dates from 1997: Bowers and Meredith, in Nature Genetics 16:84-87, compared microsatellite profiles and established the parentage at a very high likelihood ratio. The VIVC records it as confirmed by markers (no. 1929). It is the best-established parentage of the five founding varieties in this corpus.

One technical caveat: nuclear microsatellite markers do not say which parent carried the seed. The order in which the pair is stated therefore has no biological meaning.

That a black grape and a white one should cross is unremarkable — berry colour turns on a handful of alleles — and it is a useful reminder that varietal kinship is read in DNA, not in the glass.

In the vineyard

A vigorous vine with long, hard wood: pruning is slow and pulling out the canes is labour-intensive. It wants gravelly, free-draining, slightly acid, well-exposed soils that can bank the day's heat and give it back at night. That is precisely a description of the Günzian mounds of the Médoc, and it is no accident that the variety became what it is there.

It stands up well to grey rot — its thick skin protects it — but is highly susceptible to trunk diseases, eutypa dieback and esca, as well as to powdery mildew. On cold, damp soils fruit set is poor and ripeness simply does not arrive.

Its historic advantage, in a maritime climate where harvest is often wet, is that rot resistance: it can wait. Its matching weakness is that when autumn never comes, it waits for nothing.

In the glass

Deep colour, close to opaque in youth, with remarkable colour stability over time.

On the nose, blackcurrant is the historic marker of ripe fruit — the first word in the Bordeaux red vocabulary — alongside blackberry. Beside it sits graphite, the pencil-lead note associated with fine Pauillac, which describes a texture as much as a smell. A little violet, sometimes mint; eucalyptus signs Australian and Chilean Cabernet rather than Bordeaux.

Green bell pepper deserves a paragraph of its own. It comes from methoxypyrazines, IBMP in particular, first quantified in Cabernets and Bordeaux blends in 1994. In a trace it gives relief; dominant, it marks fruit that never ripened. Where the acceptable threshold lies is a genuine point of disagreement between tasting schools; this profile treats it as a marker of incomplete ripeness, the majority reading but not a universal one.

Oak brings vanilla: Cabernet Sauvignon is one of the few varieties able to absorb heavy new wood without being erased. Time does the rest, producing the classic triad of mature claret — cedar, cigar box, tobacco leaf — and then leather and truffle.

On the palate: medium to medium-high acidity (3 to 4), tannin never below 4, body and alcohol from 3 to 5. This is architecture, not a caress.

Great terroirs

The Médoc is the classic benchmark. On its Günzian gravels so late a variety ripens reliably, at a latitude where that cannot be taken for granted. Pauillac gives the most upright, most tannic version; Saint-Julien the most balanced; Margaux the most perfumed; Saint-Estèphe the most austere. The 1855 classification fixed a hierarchy that remains, in the main, legible in the glass.

Across the rest of Bordeaux it is the principal grape of the Left Bank and the Graves, a minority but real presence in Right Bank blends. It is almost always blended with Merlot, which lends flesh and volume, and Cabernet Franc, which lends scent.

Elsewhere in France it is the fourth black variety by area, behind Merlot, Grenache Noir and Syrah, widely planted in the Languedoc, Provence and the south-west.

Beyond France: Napa Valley, where it is readily varietal and sun-drenched; Chile (Maipo, Colchagua); Australia (Coonawarra, Margaret River); and coastal Tuscany, where it founded the Super Tuscans.

Commonly confused with

With Cabernet Franc, its parent: the same aromatic family, but Franc is lighter, more raspberry-scented, more floral, with looser tannin and a more readily perceived green bell pepper note.

With Merlot: the same geography and often the same glass. Merlot is rounder, plummier, lower in acid and softer in tannin. This is the commonest confusion in blind Bordeaux tasting.

With Syrah: comparable black fruit and structure, but Syrah brings black pepper and violet, and has neither cedar nor graphite.

With Chilean Carménère, long confused with Merlot in the vineyards themselves: it pushes the pyrazine register considerably further than Cabernet Sauvignon does.

Finally, Tannat and Petit Verdot can mislead through tannin alone; they lack the clean blackcurrant and the cedar.