Merlot is a dark blue-colored wine grape variety, that is used as both a blending grape and for varietal wines. The name Merlot is thought to be a diminutive of merle, the French name for the blackbird, probably a reference to the color of the grape. 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.
The earliest recorded mention of Merlot (under the synonym of Merlau) was in the notes of a local Bordeaux official who in 1784 labeled wine made from the grape in the Libournais region as one of the area’s best. In 1824, the word Merlot itself appeared in an article on Médoc wine where it was described that the grape was named after the local black bird (called merlau in the local variant of Occitan language, merle in standard) who liked eating the ripe grapes on the vine. Other descriptions of the grape from the 19th century called the variety lou seme doù flube (meaning “the seedling from the river") with the grape thought to have originated on one of the islands found along the Garonne river.
By the 19th century it was being regularly planted in the Médoc on the “Left Bank" of the Gironde. After a series of setbacks that includes a severe frost in 1956 and several vintages in the 1960s lost to rot, French authorities in Bordeaux banned new plantings of Merlot vines between 1970 and 1975.
Along with Cabernet Sauvignon, Cabernet Franc, Malbec and Petit Verdot, Merlot is one of the primary grapes used in Bordeaux wine, and it is the most widely planted grape in the Bordeaux wine regions.
Parentage and relationship to other grapes
Cabernet Franc, one of the parent varieties of Merlot. In the late 1990s, researchers at University of California, Davis showed that Merlot is an offspring of Cabernet Franc and is a half-sibling of Carménère, Malbec and Cabernet Sauvignon. The identity of the second parent of Merlot wouldn’t be discovered till the late 2000s when an obscure and unnamed variety, first sampled in 1996 from vines growing in an abandoned vineyard in Saint-Suliac in Brittany, was shown by DNA analysis to be the mother of Merlot.
This grape, later discovered in front of houses as a decorative vine in the villages of Figers, Mainxe, Saint-Savinien and Tanzac in the Poitou-Charentes was colloquially known as Madeleina or Raisin de La Madeleine due to its propensity to be fully ripe and ready for harvest around the July 22nd feast day of Mary Magdalene. As the connection to Merlot became known, the grape was formally registered under the name Magdeleine Noire des Charentes. Through its relationship with Magdeleine Noire des Charentes, Merlot is related to the Southwest France wine grape Abouriou, though the exact nature of that relationship (with Abouriou potentially being either a parent of Magdeleine Noire or an offspring) is not yet known.
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. It normally ripens up to two weeks earlier than Cabernet Sauvignon. 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 the viticultural hazard of Botrytis bunch rot. If bad weather occurs during flowering, the Merlot vine is prone to develop coulure. The vine can also be susceptible to downy mildew (though it has better resistance to powdery mildew than other Bordeaux varieties) and to infection by leafhopper insect varieties.
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 with some producing believing it is best to prune the vine “short" (cutting back to only a few buds).
In South Africa, plantings of Merlot have focused on cooler sites within the Paarl and Stellenbosch regions. Here the grape is the third most widely planted red grape variety, accounting for nearly 15% of all red wine grape plantings, with 6,614 hectares (16,340 acres) of Merlot in cultivation in 2008. The majority of these plantings are found in the Stellenbosch region with 2,105 hectares (5,200 acres) and Paarl with 1,289 hectares (3,190 acres). According to wine expert Jancis Robinson, South African Merlot tend to be made as a varietal in a “chocolately, glossy California style".