Marlborough is by far New Zealand's most important wine region. Situated at the northeastern tip of the South Island, this dry, sunny region produces - three-quarters of all New Zealand wine. It is particularly famous for its zesty Marlborough Sauvignon Blanc.
The region consists of two parallel valleys, the Wairau and the Awatere. The long, straight Wairau Valley is slightly longer-established than the Awatere and has a greater share of Marlborough's 58,300 acres (23,600ha) of vineyards.
Although some vines were planted by settlers in the 1870s, commercial scale viticulture did not begin in Marlborough until the 1970s, when the Auckland-based wine producer Montana (now Brancott Estate) surveyed the area and bought its first land there. The first large-scale vineyards were planted in 1973 and, despite early challenges with the region's dry soils and strong winds, Marlborough wines were already making a name for themselves by the early 1980s. Rapid expansion followed and, by 1985, Marlborough was awash in a sea of average-quality wines. A government vine-pull scheme helped to re-establish balance somewhat, during which the high-yielding Muller-Thurgau vines that once dominated the region were replaced with the now-iconic Sauvignon Blanc. Such was the success of Sauvignon Blanc here that Marlborough is widely regarded as the variety's New World home.
Marlborough Sauvignon Blanc exploded onto the world wine scene in the 1980s and 1990s. There are few New World wine regions so closely associated with a single grape variety as Marlborough is with Sauvignon Blanc (with the possible exception of Mendoza and its Malbec).
Marlborough's valleys were created millions of years ago by a large glacier. The Wairau Valley, home to the region's main center, Blenheim, and the Rapaura and Renwick sub-regions, has a warm, sunny climate cooled by winds from the Pacific Ocean. The Awatere Valley, just to the southeast, has a slightly cooler climate due to its added proximity to the ocean on both northern and eastern sides. Sea breezes are a vital part of the Marlborough terroir. Sunshine during the day is tempered by the wind, leading to a substantial diurnal temperature variation. This, along with a sunny, dry autumn, creates a long growing season, which gives the grapes times to develop full, expressive varietal character without losing their characteristic acidity.
The region's soils are geologically young and largely alluvial, having been distributed around the two valley floors by the Wairau and Awatere rivers. Gravelly soils are common on the river terraces, while silty loams can be found in the hills. These soils are excellent for viticulture because of their rapid drainage and low fertility. The vines are forced to work hard for hydration and nutrients, meaning that they focus their energy on the production of small, concentrated grapes, which translates into intensity of flavor in the finished wines.
Although Sauvignon Blanc dominates the Marlborough vineyards, several other varieties also perform well here. Among the white-wine grapes, Chardonnay, Pinot Gris and Riesling are the most common. In recent years, the region's earliest Pinot Noir vines have come of age, and are now producing some first-class wines. Marlborough Pinot Noirs are lighter and fruitier than those from Otago and Martinborough. Marlborough is also an important producer of quality sparkling wine made in the traditional method.