To concentrate flavours and colour, as with late harvests, but without sacrificing structure and acidity.
What Exactly Is Desiccation?
Quite simply, strangulation.
The stalks of the bunches of both red and white grapes are clamped on the vine before harvest, thus blocking the channels carrying various components to and from the berries. While up to 40% of the water evaporates, the natural acids and grape sugars are retained, concentrating flavours and colour.
The Desiccation Process At Solms-Delta
Vineyard management is crucial. Canopies are managed to ensure regular circulation of air, thus preventing excessive heat, disease and rot. Rows are planted in a South-Easterly direction to harness the wind to cool the vines, and the courdon wire is set almost a metre from the ground.
Grapes are allowed to ripen normally, to about 20° Balling or a little more, in order to ensure an adequate degree of phenolic ripeness. When the grapes are judged to be ready, teams of workers with long-nosed pliers are sent into the vineyard to crush the rachis of the bunches. (The rachis is the stem of the bunch that connects it to the cane of the vine.)
A single hard squeeze is applied to each rachis. This damages the channels that communicate between the berries and the vine. On the following day a second team returns to the vineyard and re-crushes the same stems, but at a 90° angle to the previous day’s action. Care is taken not to sever the bunches from the vine. This is a labour-intensive process.
All irrigation is now stopped – and we pray for dry, windy conditions, which accelerate the dehydration of the bunches.
The natural acids are captured in the berries, along with the grape sugars; but over a period of about 3-6 weeks up to 40% of the water content evaporates.
When the berries show the desired flavour profile, they are selectively picked. Special care is taken that no berries are lost in the process, as they are very fragile at this stage and can easily separate from the stalks.
Yield is carefully controlled; we harvest approximately two tons per hectare.
At the cellar the whole bunches are deposited in the fermentation vessel. Traditional pump-over takes place until the wine is completely fermented. An extended period of maceration then occurs. This is monitored very carefully, to avoid spoilage.
Prof Mark Solms, custodian of the family farm and prime mover in its revitalisation, refers to himself as an ‘outsider’. By this he means he has neither formal training nor preconceived ideas on winemaking. But as an ardent wine lover, scientist and scholar, he has read widely on the subject.
Conscious of the Cape’s ‘Mediterranean’ climate, he noted references to a common practice in ancient Greece (and a particular speciality of Crete): twisting the stalks of bunches on the vine before the harvest to concentrate the flavours and intensity of the grapes.
This custom spread through ancient wine-making cultures of the Mediterranean. When the merchants of Venice, the great wine importers of the 15th and 16th centuries, were deprived of their Middle Eastern supplies by the Turks, they encouraged the development of vineyards around Verona and south of Padua. Badolino, Valpolicella and Soave began to make high-alcohol wines by half-drying their grapes – a tradition that persists in Recioto and Amarone.
Desiccation was still common in the 18th century: in France, the Abbé Bellet, writing about botrytis in the early 1700s, mentions that in Italy and Provence, grapes for sweet wine were over-ripened by twisting their stems and leaving them on the vine. After that, silence.
Professor Solms saw the almost-forgotten process as a means of creating a specific signature for Solms-Delta that seemed ideally suited to climatic conditions in the Franschhoek valley.
While his decision to plant only Rhône varieties on the farm met with expert approval and was endorsed by site-specific analysis of the terroir, his plans to desiccate the grapes were greeted with scepticism. He himself was forced to go into the vineyards with pliers to prove his point.