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. 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).
While Merlot is made across the globe, there tends to be two main styles. The "International style" favored by many New World wine regions tends to emphasize late harvesting to gain physiological ripeness and produce inky, purple colored wines that are full in body with high alcohol and lush, velvety tannins with intense, plum and blackberry fruit. While this international style is practiced by many Bordeaux wine producers, the traditional "Bordeaux style" of Merlot involves harvesting Merlot earlier to maintain acidity and producing more medium-bodied wines with moderate alcohol levels that have fresh, red fruit flavors (raspberries, strawberries) and potentially leafy, vegetal notes.
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 Occitan language) 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.
It was first recorded in Italy around Venice under the synonym Bordò in 1855. The grape was introduced to the Swiss, from Bordeaux, sometime in the 19th century and was recorded in the Swiss canton of Ticino between 1905 and 1910. In the 1990s, Merlot saw an upswing of popularity in the United States. Red wine consumption, in general, increased in the US following the airing of the 60 Minutes report on the French Paradox and the potential health benefits of wine and, possibly, the chemical resveratrol. The popularity of Merlot stemmed in part from the relative ease in pronouncing the name of the wine as well as its softer, fruity profile that made it more approachable to some wine drinkers.Read more at Wikipedia