In the world of expensive wines, there is a rather strange category in which some of the most sought-after and costly bottles are made from grapes that look as though they should have gone straight to the compost heap. They are brown, shrivelled, furry in places and about as visually appetising as a two-week-old forgotten polony sandwich in the bottom of a school bag, yet these decidedly rotten-looking grapes can produce some of the most complex and long-lived sweet wines in the world.
The culprit is Botrytis cinerea, the fungus responsible for what we call noble rot. The important word is noble, because exactly the same fungus has a considerably less glamorous alter ego. Under the wrong conditions it causes grey rot, the destructive bunch rot that grape growers spend considerable amounts of time and money trying to prevent. Get the weather exactly right, however, and the fungus changes from vineyard enemy into winemaker’s accomplice, concentrating the grapes while also altering their flavour and texture in ways that can produce remarkable wines.
The best examples have a fascinating contradiction at their core: they can be enormously rich and intensely sweet without feeling heavy or syrupy.
This is where acidity becomes crucial, and it is one of the main reasons Chenin Blanc is such a strong candidate for Noble Late Harvest production in South Africa. Chenin naturally retains high acidity, ripens relatively late and is also susceptible to Botrytis, a combination that can be problematic in normal wine production but becomes extremely useful when noble rot is the objective.
Chenin’s relatively compact bunches can trap moisture, which means South African viticulturists normally have to manage the canopy carefully to reduce the risk of Botrytis and sour rot. There is a saying under farmers that you only need one cloud in the sky for Chenin Blanc to start rotting. In a season where noble rot is desired, however, that same susceptibility can become an advantage. The variety also has a naturally broad flavour spectrum, with apple, pear, quince, citrus and stone-fruit characters. Botrytis then adds another layer of complexity, bringing honey, marmalade, dried fruit, spice and savoury notes into the wine. In effect, Chenin gives the fungus a particularly interesting base to work with.
South Africa also has another major advantage when it comes to Chenin: we already know the variety exceptionally well. That experience matters when dealing with something as unpredictable as noble rot. Nederburg demonstrated the potential very early on with Edelkeur, made from botrytised Chenin Blanc, which helped establish South Africa’s Noble Late Harvest category with the 1969 vintage.
This naturally raises the question (and kind of answers them) of why Furmint, one of the great noble-rot varieties of the world, never really took off in South Africa. Furmint is the principal grape behind Hungary’s famous Tokai wines and, on paper, appears almost perfect for the job. It has naturally high acidity, ripens late and is particularly well suited to shrivelling and Botrytis. In Tokai it can produce extraordinarily concentrated wines while still retaining enough freshness to age for decades.
South Africa has experimented with Furmint, with small plantings having existed in areas such as the Swartland and Stellenbosch, and specialist producers have at times made Tokai-inspired wines from it. However, it never progressed much beyond experimental status, and there is probably no single dramatic reason for this. The most obvious issue is that Furmint arrived without the viticultural infrastructure, market recognition or accumulated experience that Chenin already had. Planting a new cultivar means sourcing suitable plant material, learning how it performs in different soils and climates, and waiting years before understanding whether it has been planted in the right place. All of this takes time and money, while South African producers already had Chenin Blanc available and capable of doing essentially the same job.
Climate is another important factor. Tokai benefits from a very particular autumn environment in which humidity and morning mist encourage Botrytis infection, followed by conditions that allow the berries to dry and shrivel rather than simply collapse into destructive rot. South Africa’s generally dry summer climate makes that sequence far less predictable. Noble rot certainly occurs here, but it is often an opportunistic event rather than something a producer can confidently expect from the same vineyard every year. Botrytis may appear in Chenin and other late-ripening white varieties, but whether it develops into useful noble rot or damaging bunch rot depends heavily on what the weather does afterwards. Planting Furmint therefore would not magically turn Paarl or Stellenbosch into Tokai.
Picking grapes one berry at a time
Even when the weather cooperates, producing noble-rot wines is painfully inefficient. Botrytis does not infect an entire vineyard at the same time, so one berry may be perfectly shrivelled while the one next to it is still healthy and another has already deteriorated too far. Harvesters therefore have to move through the vineyard repeatedly, selecting only those berries or bunches that have reached the correct stage of infection and concentration.
Once those tiny shriveled berries reach the cellar, another problem appears: there is very little juice left in them. Pressing botrytised fruit is effectively like trying to press raisins, and the juice recovery can be extremely low. Producers therefore face low vineyard yields, repeated and expensive hand harvesting, careful selection and then poor extraction at the press. Suddenly the price of that little 375 ml bottle begins to make considerably more sense.
What does noble rot actually taste like?
This is where Noble Late Harvest becomes much more interesting than simply making wine from grapes with very high sugar levels. Botrytis does not only remove water and make the fruit sweeter, as the fungus penetrates the berry skin and the grape gradually shrivels, the chemistry and flavour of the fruit change as well.
A good botrytised wine can show aromas and flavours of honey, dried apricot, yellow peach, orange marmalade, candied citrus peel and quince, often with ginger, spice, beeswax or lanolin developing alongside them. There can also be stranger and more savoury notes, including dried flowers, rooibos-like herbal characters, mushrooms, earth and even slightly medicinal nuances. These are often the characteristics that separate a serious botrytised wine from something that merely tastes like sweet grape juice.
Taken individually, these flavours can sound like an unusual shopping list, but together they create the unmistakable character of noble rot. There is also a significant textural difference. Botrytised wines can feel almost oily or glycerol-rich in the mouth, with the sugar providing weight while changes caused by the fungus add further viscosity and complexity. When balanced by sufficient acidity, the result is not simply sweet wine, but something far more layered, intense and distinctive.
Articles