Central Otago is one of the most famous New Zealand wine regions, located in the Southern part of South Island. The area is famous for the production of high quality Pinot Noirs exported worldwide, but it hides some white wines of outstanding quality.
The region displays an unusual climate and landscape for grape growing. In fact, it is surrounded by mountain ranges that create a rain shadow all over the Central Otago plateau. It means that the mountain ranges will block clouds of rain to get over the area, ensuring a dry climate all over the year. Central Otago seems like a desert, even though it is located in one of the coolest parts of New Zealand.
Dicey Wines make the most of the desert climate in their Bannockburn Vineyard.
The dry climate and the high diurnal range (the difference between daytime and nighttime temperatures), typical of the desertic areas, result in high water stress for the vines, that will struggle to find some water during the hot summer season. However, this means that the grapes will be of really high quality, concentrated and with low yields per hectare.
The high diurnal range, in particular, is crucial for maintaining the acidity of the white grape varieties in this hot and dry climate.
Getting to the heart of the discussion about Central Otago white grape varieties, impossible not to immediately mention the Chardonnay.
It is a versatile grape variety that often grows well in the same climate of the Pinot Noir. In fact, they are both native of Burgundy region in France. The climate of Central Otago allows the wineries to harvest fully ripe Chardonnay grapes, thanks to the typical hot summers, with extraordinary high acidity kept thanks to the high diurnal range. Chardonnay is usually aged in oak barrels, following the Burgundy style, but there are also some examples of steely and cutting Chardonnays produced near the mountains.
However, the key role regarding white wines is played by Riesling. This aromatic grape variety has the chance to display all its beautiful aromas thanks to the hot climate, keeping its high acidity and pungent texture. The wineries often do a short maceration on the skins, in order to extract more aroma compounds and creating a concentrated wine. They can easily do this because the Riesling ripens fully in Central Otago, so there is not the risk to extract bitter compounds from the skins.
Rieslings from Central Otago can be produced in a wide range of styles, from dry to sweet; however, in the last decades dry Rieslings are mainly produced to reach higher quality and to satisfy an International market.
Sauvignon Blanc is also produced in Central Otago, even though the homeland for Sauvignon Blanc is the well-known Marlborough. Sauvignon Blanc can easily maintain its typical herbal notes thanks to the high diurnal range, but it tends to get riper compared to Marlborough. Thanks to the hot temperatures experienced during the day, the Sauvignon Blanc could also display aromas of passion fruit, pineapple and white musk, typical of Sauvignon Blancs grown in warm climates. Here, the Sauvignon Blanc has high acidity and a refreshing aftertaste, but it is not steely and cutting; moreover, some wineries produce a barrel-aged Sauvignon Blanc with high complexity and vibrant acidity on the palate.