Cabernet Sauvignon

Cabernet Sauvignon () is one of the world's most widely recognized red wine grape varieties. It is grown in nearly every major wine producing country among a diverse spectrum of climates from Australia and British Columbia, Canada to Lebanon's Beqaa Valley. Cabernet Sauvignon became internationally recognized through its prominence in Bordeaux wines, where it is often blended with Merlot and Cabernet Franc. From France and Spain, the grape spread across Europe and to the New World where it found new homes in places like California's Santa Cruz Mountains, Paso Robles, Napa Valley, New Zealand's Hawke's Bay, South Africa's Stellenbosch region, Australia's Margaret River, McLaren Vale and Coonawarra regions, and Chile's Maipo Valley and Colchagua. For most of the 20th century, it was the world's most widely planted premium red wine grape until it was surpassed by Merlot in the 1990s.
However, by 2015, Cabernet Sauvignon had once again become the most widely planted wine grape, with a total of under vine worldwide.

Despite its prominence in the industry, the grape is a relatively new variety, the product of a chance crossing between Cabernet Franc and Sauvignon blanc during the 17th century in southwestern France. Its popularity is often attributed to its ease of cultivation—the grapes have thick skins and the vines are hardy and naturally low yielding, budding late to avoid frost and resistant to viticultural hazards such as rot and insects—and to its consistent presentation of structure and flavours which express the typical character ("typicity") of the variety. Familiarity has helped sell Cabernet Sauvignon wines to consumers, even from unfamiliar wine regions. Its widespread popularity has also contributed to criticism of the grape as a "colonizer" that takes over wine regions at the expense of indigenous grape varieties.

The classic profile of Cabernet Sauvignon tends to be full-bodied wines with high tannins and noticeable acidity that contributes to the wine's aging potential. In cooler climates, Cabernet Sauvignon produces wines with blackcurrant notes that can be accompanied by green bell pepper notes, mint and cedar, which will all become more pronounced as the wine ages. In more moderate climates, the black currant notes are often seen with black cherry and black olive notes, while in very hot climates, the currant flavours can veer towards the over-ripe and "jammy" side. In parts of Australia, particularly the Coonawarra wine region of South Australia, Cabernet Sauvignon wines tend to have characteristic eucalyptus or menthol notes.Wine & Spirits Education Trust ''"Wine and Spirits: Understanding Wine Quality"'' pgs 6-9, Second Revised Edition (2012), London,

History and origins

For many years, the origin of Cabernet Sauvignon was not clearly understood, and many myths and conjectures surrounded it. Until recently, the grape was rumoured to have ancient origins, perhaps even being the ''Biturica'' grape used to make ancient Roman wine and referenced by Pliny the Elder. This belief was widely held in the 18th century, when the grape was also known as ''Petite Vidure'' or ''Bidure'', apparently a corruption of ''Biturica''. There was also a belief that ''Vidure'' was a reference to the hardwood (French ''vigne dure'') of the vine, with a possible relationship to Carménère which was once known as ''Grand Vidure''. Another theory was that the grapevine originated in the Rioja region of Spain.

While the period when the name ''Cabernet Sauvignon'' became more prevalent over ''Petite Vidure'' is not certain, records indicate that the grape was a popular Bordeaux planting in the 18th century Médoc region. The first estates known to have actively grown the variety (and the likely source of Cabernet vines for other estates) were Château Mouton and Château d'Armailhac in Pauillac.

The grape's true origins were discovered in 1996 with the use of DNA typing at the UC Davis Department of Viticulture and Enology by a team led by Dr. Carole Meredith. The DNA evidence determined that Cabernet Sauvignon was the offspring of Cabernet franc and Sauvignon blanc and was most likely a chance crossing that occurred in the 17th century. Before this discovery, this origin had been suspected from the similarity of the grapes' names and the fact that Cabernet Sauvignon shares similar aromas with both grapes—such as the blackcurrant and pencil box aromas of Cabernet franc and the grassiness of Sauvignon blanc. In 2016, scientists at the UC Davis announced they had sequenced a draft of the whole genome of the Cabernet Sauvignon grape, the first genome of a commercial wine-producing grape to be sequenced.

Offspring and White Cabernet

While not as prolific in mutating as Pinot noir, nor as widely used in the production of offspring, Cabernet Sauvignon has been linked to other grape varieties. In 1961, a cross of Cabernet Sauvignon and Grenache produced the French wine grape Marselan. Cygne blanc is a white-berried seedling of Cabernet Sauvignon that was discovered in 1989 growing in a garden in Swan Valley, Western Australia. Cabernet blanc is a crossing of Cabernet Sauvignon and an unknown hybrid grape variety that was discovered in Switzerland in the late 20th century.

In 1977 a vine producing 'bronze' grapes was found in the vineyards of Cleggett Wines in Australia. They propagated this mutant, registered it under the name of Malian, and sold pale red wines under that name. In 1991 one of the Bronze Cabernet vines started producing white grapes. Cleggett registered this "White Cabernet" under the name of Shalistin. Compared to its Cabernet parent, Malian appears to lack anthocyanins in the subepidermal cells but retains them in the epidermis, whereas Shalistin has no anthocyanins in either layer. The team that went on to discover the VvMYBA1 and VvMYBA2 genes that control grape colour have suggested that a gene involved in anthocyanin production has been deleted in the subepidermis of Malian, and then subepidermal cells invaded the epidermis to produce Shalistin.

During a series of trials between 1924 and 1930, the pollen of Cabernet Sauvignon was used to fertilize Glera vines (the white wine grape used to make the sparkling wine Prosecco) to create the red Italian wine grape Incrocio Manzoni 2.15.

In 1972, the Australian agency CSIRO crossed Cabernet Sauvignon grapes with the Spanish Sumoll variety to create three new varieties: Cienna, Tyrian and Rubienne.

In 1983, Cabernet Sauvignon was crossed with the white German wine grape Bronner to create the white wine grape Souvignier gris.

Viticulture

While Cabernet Sauvignon can grow in a variety of climates, its suitability as a varietal wine or as a blend component is strongly influenced by the warmth of the climate. The vine is one of the last major grape varieties to bud and ripen (typically 1–2 weeks after Merlot and Cabernet franc), and the climate of the growing season affects how early the grapes will be harvested. Many wine regions in California give the vine an abundance of sunshine with few problems in ripening fully, which increases the likelihood of producing varietal Cabernet wines. In regions like Bordeaux, under the threat of inclement harvest season weather, Cabernet Sauvignon is often harvested a little earlier than ideal and blended with other grapes to fill in the gaps. In some regions, the climate will be more important than the soil. In regions that are too cool, there is a potential for more herbaceous and green bell pepper flavours from less than ideally ripened grapes. In regions where the grape is exposed to excess warmth and over-ripening, there is a propensity for the wine to develop flavours of cooked or stewed blackcurrants.

The Cabernet grape variety has thrived in a variety of vineyard soil types, making the consideration of soil less of a concern, particularly for New World winemakers. In Bordeaux, the soil aspect of '' terroir'' was historically an important consideration in determining which of the major Bordeaux grape varieties were planted. While Merlot seemed to thrive in clay- and limestone-based soils (such as those of the Right Bank regions of the Gironde estuary), Cabernet Sauvignon seemed to perform better in the gravel-based soil of the Médoc region on the Left Bank. The gravel soils offered the benefit of being well drained while absorbing and radiating heat to the vines, aiding ripening. Clay- and limestone-based soils are often cooler, allowing less heat to reach the vines, and delaying ripening. In regions where the climate is warmer, there is more emphasis on soil that is less fertile, which promotes less vigour in the vine, which can keep yields low. In the Napa Valley wine regions of Oakville and Rutherford, the soil is more alluvial and dusty. Rutherford Cabernet Sauvignon has been often quoted as giving a sense of ''terroir'' with a taste of "Rutherford dust". In the South Australian wine region of Coonawarra, Cabernet Sauvignon has produced vastly different results from grape vines planted in the region's terra rosa soil – so much so that the red soil is considered the "boundary" of the wine region, with some controversy from wine growers with Cabernet Sauvignon, planted on red soil.

In addition to ripeness levels, the harvest yields can also have a strong influence on the resulting quality and flavours of Cabernet Sauvignon wine. The vine itself is prone to vigorous yields, particularly when planted on the vigorous SO4 rootstock. Excessive yields can result in less concentrated and flavorful wine with flavours more on the green or herbaceous side . In the 1970s, a particular clone of Cabernet Sauvignon that was engineered to be virus free was noted for its very high yields-causing many quality-conscious producers to replant their vineyards in the late 20th century with different clonal varieties. To reduce yields, producers can plant the vines on less vigorous rootstock and also practice green harvesting with aggressive pruning of grape clusters soon after '' veraison''.

In general, Cabernet Sauvignon has good resistance to most grape diseases, powdery mildew being the most noted exception. It is, however, susceptible to the vine diseases '' Eutypella scoparia'' and excoriose.

The "green bell pepper" flavor

A couple of noted Cabernet Sauvignon flavours are intimately tied to viticultural and climate influences. The herbaceous or green bell pepper flavour is most widely recognised, caused by pyrazines, which are more prevalent in under-ripened grapes. Pyrazine compounds are present in all Cabernet Sauvignon grapes and are gradually destroyed by sunlight as the grape continues to ripen. To the human palate, this compound is detectable in wines with pyrazine levels as low as 2 nanograms (ng) per litre. At the time of ''veraison'', when the grapes first start to ripen fully, there is the equivalent pyrazine level of 30 ng/L. In cooler climates, getting Cabernet Sauvignon grapes to ripen fully to the point where pyrazine is not detected is difficult. The green bell pepper flavour is not considered a wine fault, but it may not be desirable to all consumers' tastes. The California wine region of Monterey was noted in the late 20th century for its very vegetal Cabernet Sauvignon with pronounced green pepper flavour, earning the nickname "Monterey veggies". In addition to its cool climate, Monterey is also prone to being very windy, which can shut down the grape vines and further inhibit ripeness.

Two other well-known Cabernet Sauvignon flavours are mint and eucalyptus. Mint flavours are often associated with wine regions that are warm enough to have low pyrazine levels but are still generally cool, such as Australia's Coonawarra region and some areas of Washington State. Some believe that soil could also contribute to the minty notes since the flavour also appears in some wines from the Pauillac region but not from the similar climate of Margaux