Behind the Soils of Wildeberg
How do you go about converting an unused field into a vineyard fit for growing world-class grapes?
This was the challenge that faced the team at Wildeberg when the estate was founded in 2016. With years of winemaking and viticultural experience behind them and with the help of modern technology, they set about the task…
Getting the lay of the land
One of the most powerful tools in a modern winemaker’s toolkit, solar radiation maps show the amount of sunlight received per unit area in different parts of the field; in other words, the hottest and coolest parts of the vineyard. This is a key step in understanding which areas are best suited to which varieties.
“In the coolest parts of the vineyard we planted whites to keep freshness in the wine, and Rhône varieties to give some spice to the Syrah and Durif (Petit Sirah). Malbec and Cabernet Franc were planted in the sites with higher solar radiation to help them ripen and to reduce the chance of ‘green’ notes in the final wine.” – JD Rossouw, Wildeberg Head Winemaker
Beneath our feet
There is a lot to consider with soil type: water holding capacity, heat retention, mineral and organic content, erosion, compaction, and so on. In any kind of horticulture, soil is as important to a plant’s survival as any other climatic influence. In viticulture it is a huge contributing factor to the notion of ‘terroir’* and something that needs to be considered carefully before planting.
At Wildeberg we discovered that the site was split almost evenly over two main soil types: Kroonstad and Cartref. While soil science is extremely complex (not to mention a continuing point of debate amongst industry experts), broadly speaking Kroonstad has high clay content and thus more water-retaining ability, so will tend to give fuller wines. Cartref, on the other hand, is granitic and contains more rocks, which will contribute minerality and finesse to a wine.
From the two reports, it became clear that we had a somewhat unique opportunity at Wildeberg. The split of soil types runs perpendicular to the dispersal of heat in the vineyard, meaning that each soil type has both warmer and cooler areas. While soil has a significant impact on wine style, temperature and sun exposure are key to the maturation and phenolic ripening of grapes, so vine planting is decided firstly according to temperature. At Wildeberg this means that each grape variety planted runs over the two different soil types.
“We plan to harvest and ferment them separately, so Kroonstad Semillon and Cartref Semillion apart. They will then be blended, which will create a wine with more complexity and personality.” – JD Rossouw
Planting
Once planting began, we found that we were once more presented with a special situation. Several large stones were unearthed, but rather than removing them from the site we chose to make our very own clos outside the house. A clos is a vineyard enclosed within a wall, which can help to protect the vines and improve the mescoclimate, producing unique grapes and adding a distinctive character to the final wine. The Clos at Wildeberg is just under a hectare of Cartref soil planted with Semillon bush vines.
Wine is a combination of science, nature and expertise and it’s fascinating to see the importance of every aspect of building a vineyard from scratch and how decisions made now will impact wines made in a few years’ time. We can’t wait to see what the first home-grown wines of Wildeberg will bring!