The ‘big three’ grapes of red Bordeaux wine

Viticulture in the Bordeaux wine region is the complete antithesis of Burgundy. The former practices the art of blending, while the latter prefers to maintain a strict demarcation of its terroirs, producing single-site and single-varietal wines that are a distinct expression of the soil and landscape.

This is not the Bordeaux way. A blend of grape varieties (typically a varying mixture of Cabernet Sauvignon, Merlot and Cabernet Franc) is crafted according to the vintage conditions in Bordeaux, tailored by the house style of the chateaux based on which varieties work best in their vineyards. Chateau Petrus and Le Pin in Pomerol are solely based on the Merlot grape, but single-varietal wine is generally rare in Bordeaux’s capricious climate.

Indeed, it is the threat of an inclement vintage that is most directly responsible for maintaining this attachment to blending. The custom acts as an insurance policy. If a large volume of Cabernet Sauvignon fails to ripen, then there is still a chance that Merlot will make it through to harvest. There have been several vintages over the past 30 years where one variety has been eliminated due to frost attacks or hail. It is hardly surprising, therefore, that growers are reluctant to embrace mono-varietal plantings. The 2013 harvest, for example, was carried out under torrential rain, ensuring that only the best winemakers managed to craft good wines that year (and several did). Chateau Gloria is one such property that triumphed, releasing a medium-bodied and supple 2013 red wine with remarkable length and finesse.

The Bordeaux blend culture is also partially based on a certain romanticism. The varietal mix represents the ‘persona’ of a chateau, and it takes a brave new owner to tamper with their inheritance. In a model growing season, it is plausible that an estate in Saint-Julien, for example, could produce a 100% Cabernet Sauvignon wine. Whether they would want to is another matter; Bordeaux winemakers of all stripes often argue that blending grapes, even if every variety ripens perfectly, enhances complexity. Yet both the Left and Right Bank of the Bordeaux region have their priorities and viticultural preferences.

Cabernet Sauvignon

Cabernet Sauvignon is king in the Medoc region. This fine wine powerhouse, situated north of the city of Bordeaux, plays host to famous appellations such as Margaux, Pauillac and Saint-Julien. The majority of estates prefer to make wines containing at least 70% Cabernet Sauvignon unless the weather precludes this. It has a natural affinity with the well-drained gravel terroir found throughout the southern and central parts of the zone. The gravel reflects heat, enabling this late-ripening variety to achieve good phenolic ripeness by the date of the harvest, all being well. Indeed, the red grape has been the backbone of the Medoc since the mid-nineteenth century, and with good reason. It is capable of producing some of the most complex and long-lived wines on earth, with its beguiling flavours of blackcurrant, cedar and black cherry. Some years it may not ripen fully, but when it does the volume of tannin and colour packed into its thick skins is unparalleled.

Cabernet Sauvignon is a magnificent grape variety, but it is not without its challenges. It is susceptible to fungal diseases such as powdery mildew, which can significantly reduce the potential yield. The grape’s tendency to ripen late in the season can be a disadvantage in wetter vintages, as the winemaker may encounter rot in the vineyard and dilution in the fermenter. Nevertheless, because of its unrivalled ability to age, very few chateaux in the Medoc would even consider relegating Cabernet Sauvignon to a minor role. Fresh, vibrant Medoc vintages from the nineteenth century are not unheard of, which is a rarity in the world of fine wine. This is due to the high level of tannin inherent to Cabernet Sauvignon’s tiny berries, which require ageing. It is partly for this reason that growers in the Medoc have traditionally blended in smaller amounts of Merlot to soften this tannic austerity, particularly in cooler vintages.

The 2016 vintage of Lacoste Borie exemplifies everything that is wonderful about Pauillac-grown Cabernet Sauvignon. Many wine regions are making excellent Cabernet wines today, but only Bordeaux can offer that inimitable balance between power and finesse. Structured and yet approachable, the wine offers delicious aromas of cassis, cedar and damson jam.

Merlot

Merlot is by far the most important red variety of Bordeaux’s Right Bank. Growers in Saint-Émilion and Pomerol, two appellations located east of the Dordogne river, greatly admire the grape’s natural opulence, soft tannins and flavours of plum, blackberry and raspberry. It has traditionally played a major role in almost every wine made in Saint-Émilion, as Merlot responds exceptionally well to the zone’s (overall) predominance of clay/limestone soils. Cabernet Sauvignon, however, will often struggle to ripen on these colder soils, which is why the grape has historically been used in relatively small quantities in the Right Bank.

There are other advantages to growing Merlot. It ripens sooner and more reliably than Cabernet Sauvignon in cooler vintages, and rarely boasts an excess of astringent or harsh tannin, even after a difficult growing season. It reaches an apogee in Pomerol and Saint-Émilion, creating voluptuous, structured and gloriously hedonistic wines. It takes a stony heart not to be seduced by Merlot’s rich fruit, lush texture and often generous (but not overblown) alcohol. Chateau Les Gravieres, exclusively based on Merlot in the 2018 vintage, offers a convincing sales pitch. Managing to be supple and immensely concentrated, this incarnation of Les Gravier has a majestic nose of blueberry, chocolate, violets and mocha.

However, Merlot is not effortless to cultivate. Although it ripens about two weeks earlier than Cabernet Sauvignon, the variety is more at risk of spring frost attacks because it buds earlier, while rot during the harvest is omnipresent in wet vintages. Coulure (the failure of berries to form after flowering) and fungal diseases are also familiar maladies to seasoned Merlot growers.

But this does not deter Merlot’s passionate acolytes across the Right Bank, who continue to stake their reputation on producing wines that almost always place Merlot at the heart of the blend. Cabernet Franc can play a supporting role to add structure and freshness. Occasionally, a small amount of Cabernet Sauvignon may also be included for a dash of spice and tannic heft, but a Cabernet Sauvignon-dominant blend in the Right Bank is almost unthinkable.

Cabernet Franc

At first glance, Cabernet Franc is something of an outlier in Bordeaux’s viticultural map. This red grape variety is actually the genetic parent grape of Merlot and Cabernet Sauvignon, but rarely dominates any blend in either the Left or Right Bank (Cheval Blanc is one exception) and has attracted criticism from some quarters. Matthieu Bordes, the senior winemaker at Chateau Lagrange, believes that Cabernet Franc lacks density in comparison with Cabernet Sauvignon. The variety is notoriously difficult to grow, prone to developing several grapevine diseases, and is very fussy about where it is planted.

Cabernet Franc also has its share of passionate followers, including the owners of Angelus. The winemaking team at Chateau Carmes Haut-Brion are enthusiastic adopters of the grape, arguing it contributes valuable acidity, freshness and structure to their wines. The best examples are astonishingly good, full of complex aromas of red fruits, graphite, bell pepper and sour cherry. With age comes tertiary flavours of wood smoke, coffee and gravel. When Cabernet Franc is added to the wines of the Medoc, Saint-Émilion and Pomerol, it can heavily influence the wine’s perfume and acid line, adding much-needed balance in warmer vintages.