Wine Grapes: Chardonnay

Chardonnay is a green-skinned grape variety used to make white wine. It originated in the Burgundy wine region of eastern France but is now grown wherever wine is produced, from England to New Zealand. For new and developing wine regions, growing Chardonnay is seen as a "rite of passage" and an easy entry into the international wine market.

The Chardonnay grape itself is very neutral, with many of the flavors commonly associated with the grape being derived from such influences as terroir and oak. It is vinified in many different styles, from the lean, crisply mineral wines of Chablis, France to New World wines with oak, and tropical fruit flavors.

Modern DNA fingerprinting research at University of California, Davis, now suggests that Chardonnay is the result of a cross between the Pinot and Gouais Blanc (Heunisch) grape varieties. It is believed that the Romans brought Gouais Blanc from Croatia, and it was widely cultivated by peasants in Eastern France. The Pinot of the French aristocracy grew in close proximity to the Gouais Blanc, giving both grapes ample opportunity to interbreed. Since the two parents were genetically distant, many of the crosses showed hybrid vigour and were selected for further propagation. These "successful" crosses included Chardonnay and siblings such as Aligoté, Aubin Vert, Auxerrois, Bachet noir, Beaunoir, Franc Noir de la-Haute-Saône, Gamay Blanc Gloriod, Gamay noir, Melon, Knipperlé, Peurion, Roublot, Sacy and Dameron.

Chardonnay has a wide-ranging reputation for relative ease of cultivation and ability to adapt to different conditions. The grape is very "malleable", in that it reflects and takes on the impression of its terroir and winemaker. It is a highly vigorous vine, with extensive leaf cover which can inhibit the energy and nutrient uptake of its grape clusters. Vineyard managers counteract this with aggressive pruning and canopy management. When Chardonnay vines are planted densely, they are forced to compete for resources and funnel energy into their grape clusters. In certain conditions the vines can be very high-yielding, but the wine produced from such vines will suffer a drop in quality if yields go much beyond 4.5 tons per acre (80 hl/ha). Producers of premium Chardonnay limit yields to less than half this amount. Sparkling wine producers tend not to focus as much on limiting yields, since concentrated flavors are not as important as the wine's finesse.

While Chardonnay can adapt to almost all vineyard soils, the three it seems to like most are chalk, clay and limestone, all very prevalent throughout Chardonnay's traditional "homeland". The Grand crus of Chablis are planted on hillsides composed of Kimmeridgian marl, limestone and chalk. The outlying regions, falling under the more basic "Petit Chablis" appellation, are planted on portlandian limestone which produces wines with less finesse. Chalk beds are found throughout the Champagne region, and the Côte-d'Or has many areas composed of limestone and clay. In Burgundy, the amount of limestone to which the Chardonnay vines are exposed also seems to have some effect on the resulting wine. In the Meursault region, the premier cru vineyards planted at Meursault-Charmes have topsoil almost 78 inches (2.0 m) above limestone and the resulting wines are very rich and rounded. In the nearby Les Perrieres vineyard, the topsoil is only around 12 inches (30 centimeters) above the limestone and the wine from that region is much more powerful, minerally and tight, needing longer in the bottle to develop fully. In other areas, soil type can compensate for lack of ideal climate conditions. In South Africa for example, regions with stonier, shaley soils and high clay levels tend to produce lower-yielding and more Burgundian-style wine, despite having a discernibly warmer climate than France. In contrast, South African Chardonnay produced from more sandstone-based vineyards tend to be richer and more weighty.

Confusion with Pinot blanc

Due to some ampelographical similarities, Pinot Blanc and Chardonnay were often mistaken for each other and even today share many of the same synonyms. The grape vines, leaves and clusters look identical at first glance but there are some subtle differences. The most visible of these can be observed as the grapes are ripening, with Chardonnay grapes taking on a more golden-green color than Pinot Blanc grapes. On closer inspection, the grapevine will show slight differences in the texture and length of the hairs on the vine's shoot, and the veins of a Chardonnay leaf are "naked" near the petiolar sinus – the open area where the leaf connects to the stem is delineated by veins at the edge. Cabernet Sauvignon is one of the few other Vitis vinifera grape vines to share this characteristic. This confusion between Pinot blanc and Chardonnay was very pervasive throughout northern Italy, where the two vines grew interspersed in the vineyard and were blended in winemaking. Not until 1978 did the Italian government dispatch researchers to try to distinguish the two vines. A similar situation occurred in France, with the two vines being commonly confused until the mid 19th century, when ampelographers began combing through the vineyards of Chablis and Burgundy, identifying the true Chardonnay and weeding out the Pinot Blanc.