Merlot

Merlot is a darkly blue-coloured wine grape, that is used as both a blending grape and for varietal wines. The name Merlot is thought to derive from the Old French word for young blackbird, merlot, a diminutive of merle, the blackbird (Turdus merula), probably from the color of the grape. Merlot-based wines usually have medium body with hints of berry, plum, and currant. Its softness and "fleshiness", combined with its earlier ripening, makes Merlot a popular grape for blending with the sterner, later-ripening Cabernet Sauvignon, which tends to be higher in tannin.

Along with Cabernet Sauvignon, Cabernet Franc, Malbec and Petit Verdot, Merlot is one of the primary grapes in Bordeaux wine where it is the most widely planted grape. Merlot is also one of the most popular red wine varietals in many markets. This flexibility has helped to make it one of the world's most planted grape varieties. As of 2004, Merlot was estimated to be the third most grown variety at 260,000 hectares (640,000 acres) globally, with an increasing trend. This puts Merlot just behind Cabernet Sauvignon's 262,000 hectares (650,000 acres).

Merlot grapes are identified by their loose bunches of large berries. The color has less of a blue/black hue than Cabernet Sauvignon grapes and with a thinner skin and fewer tannins per unit volume. Also compared to Cabernet, Merlot grapes tend to have a higher sugar content and lower malic acid. Merlot thrives in cold soil, particularly ferrous clay. The vine tends to bud early which gives it some risk to cold frost and its thinner skin increases its susceptibility to Botrytis bunch rot. If bad weather occurs during flowering, the Merlot vine is prone to develop coulure. It normally ripens up to two weeks earlier than Cabernet Sauvignon. Water stress is important to the vine with it thriving in well drained soil more so than at base of a slope. Pruning is a major component to the quality of the wine that is produced. Wine consultant Michel Rolland is a major proponent of reducing the yields of Merlot grapes to improve quality. The age of the vine is also important, with older vines contributing character to the resulting wine.

A characteristic of the Merlot grape is the propensity to quickly overripen once it hits its initial ripeness level, sometimes in a matter of a few days. There are two schools of thought on the right time to harvest Merlot. The wine makers of Château Pétrus favor early picking to best maintain the wine's acidity and finesse as well as its potential for aging. Others, such as Rolland, favor late picking and the added fruit body that comes with a little bit of over-ripeness.

Food pairing

In food and wine pairings, the diversity of Merlot can lend itself to a wide array of matching options. Cabernet-like Merlots pair well with many of the same things that Cabernet Sauvignon would pair well with, such as grilled and charred meats. Softer, fruitier Merlots (particularly those with higher acidity from cooler climate regions like Washington State and Northeastern Italy) share many of the same food-pairing affinities with Pinot noir and go well with dishes like salmon, mushroom-based dishes and greens like chard and radicchio. Light-bodied Merlots can go well with shellfish like prawns or scallops, especially if wrapped in a protein-rich food such as bacon or prosciutto. Merlot tends not to go well with strong and blue-veined cheeses that can overwhelm the fruit flavors of the wine. The capsaicins of spicy foods can accentuate the perception of alcohol in Merlot and make it taste more tannic and bitter.

References

1. "Wine Business Journal listing of varietal sales.".
2.  J. Robinson (ed) The Oxford Companion to Wine Third Edition, Oxford University Press 2006, pg. 746: "Vine varieties"
3. J-M. Boursiquot; T. Lacombe; V. Laucou; S. Julliard; F-X. Perrin; N. Lanier; D. Legrand; C. Meredith et al. (2009). "Parentage of Merlot and related winegrape cultivars of southwestern France: discovery of the missing link". Australian Journal of Grape and Wine Research 15 (2): 144–155.
4. Oz Clarke Encyclopedia of Grapes pg 129–133 Harcourt Books 2001.
5. J. Robinson Vines, Grapes & Wines pg 91–94 Mitchell Beazley 1986
6. E. Goldstein "Perfect Pairings" pg 148–152 University of California Press 2006
7. J. Robinson Jancis Robinson's Wine Course Third Edition pg 142–143 Abbeville Press 2003.
8. Merlot Blanc, Vitis International Variety Catalogue

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 Canada's Okanagan Valley 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, the grape spread across Europe and to the New World where it found new homes in places like California's Napa Valley, Australia's Coonawarra region and Chile's Maipo Valley. 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.

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 resistant to rot and frost—and to its consistent presentation of structure and flavours which express the typical character ("typicity") of the variety. Familiarity and ease of pronunciation have helped to sell Cabernet Sauvignon wines to consumers, even when 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 native grape varieties.

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 is then blended with other grapes to fill in the gaps. In some regions, climate will be more important than 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 thriven in a variety of vineyard soil types, making the consideration of soil less of 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, delaying ripening. In regions where the climate is warmer, there is more emphasis on soil that is less fertile, which promotes less vigor 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 in the resulting quality and flavors 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 flavors 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.

DNA evidence has shown Cabernet Sauvignon is the result of the crossing of two other Bordeaux grape varieties— Cabernet franc and Sauvignon blanc— which has led grapevine historians, or ampelographers, to believe that the grape originated in Bordeaux. Early records indicate that the grape was a popular planting in the Médoc region during the 18th century. The loose berry clusters and thick skins of the grape provided a good resistance to rot in the sometimes wet maritime climate of Bordeaux. The grape continued to grow in popularity till the Powdery mildew epidemic of 1852 exposed Cabernet Sauvignon's sensitivity to that grape disease. With vineyards severely ravaged or lost, many Bordeaux wine growers turned to Merlot, increasing its plantings to where it soon became the most widely-planted grape in Bordeaux. As the region's winemakers started to better understand the area's terroir and how the different grape varieties performed in different region, Cabernet Sauvignon increased in plantings all along the Left Bank region of the Gironde river in the Médoc as well as Graves region, where it became the dominant variety in the wine blends. In the Right bank regions of Saint-Émilion and Pomerol, Cabernet is a distant third in plantings behind Merlot & Cabernet franc.

References 

1. Robinson, J., ed. (2006). The Oxford Companion to Wine (Third ed.). Oxford University Press. pp. 119–121
2. Clarke, Oz (2001). Encyclopedia of Grapes. Harcourt Books. pp. 47–56.