The South African Grape that Proved not to Be

Fresh from a bout of research into a few key role-players in the history of South African wine, I replaced my history and academic readings with the inner calm of catching up on the devastation of the war in Ukraine. This colourful, action-packed interlude veered into some roundabout investigation into Ukrainian wine, and an unexpected finding as to the origin of a wine grape cultivar that had always been assumed to be South African.

The variety in question is Roobernet, the most famous South African red grape crossing after Pinotage, and listed all over the local place as one of the country’s “indigenous varieties”. Roobernet is a viticultural liaison between the grapes Cabernet Sauvignon and Alicante Bouschet that was first done by CJ Orffer, Professor of Viticulture at Stellenbosch University from 1963 to 1986.

A brilliant academic consumed by his subject, between 1958 and 1964 Prof. Orffer carried out numerous wine grape crossings, and cultivar status was granted to six of these, namely Chenel, Weldra, Roobernet, Therona, Grachen and Nouvelle. He also made numerous rootstock crossings, of which the best known are US 2-1 and US 8-7.

Orffer’s legacy was fresh in my mind when reading about the wines of Ukraine, thus I had to look twice when coming across the origins of the Ukrainian grape going by the rather captivating name Odesa Black. Because there it stood: Odesa Black evolved as a crossing between, yes, Cabernet Sauvignon and Alicante Bouschet, done in 1948 at the Tairov Institute in Odesa, thus preceding Orffer’s Roobernet by some distance of time. And yet, most South African resources – official industry and other – claim the Cabernet Sauvignon/Alicante Bouschet wild child was the result of Orffer’s (indisputable) ingenuity.

Upon contacting some of the more communication-savvy folk at industry body South Africa Wine, they too were surprised, yet exceedingly co-operative, and I was sent a paper written by Orffer himself admitting that, when considering Roobernet, the initial idea was not to have Cabernet Sauvignon and Alicante Bouschet as the parents. The former, yes, but the other side was meant to be the Pontac variety.

Shortly before his death, Orffer requested Vititec – the Cape wine industry’s nursery for clones, cultivars and all things vine-related – to verify the parents of some of his crossings, as he suspected that some of the parentages had been recorded incorrectly.

Since the time of Orffer’s varietal crossings and his writing, DNA analyses of grape varieties had become de rigueur, and the great man had been alerted to all not being well with the assumed origins of his inter-cultivar activities. (Modesty in the academics of science tends to be more prevalent than in the arts, culture and literature departments, for sure.)

The parents of Roobernet were initially indicated as Cabernet Sauvignon and Pontac, the two grapes the Professor assumed he had crossed. However, for Orffer there were, in later years, indications that Pontac might not be one of the parents, with Alicante Bouschet being furthest from his mind. In fact, “due to the lower wine quality of Alicante Bouschet, it was never even considered for use as a crossing parent,” Orffer wrote in his paper to Vititec.

Morphologically, the leaves of Roobernet show very little resemblance to Alicante Bouschet and are often confused with Cabernet Sauvignon. However, Roobernet’s large bunches and high production indicated to Orffer a possible intervention by Alicante Bouschet in the Roobernet family tree. The leading authority at that time on DNA analysis in the world of viticulture was ENTAV (Établissement National Technique pour l’Amélioration de la Viticulture) in France.

This body took a look at Roobernet and, using their science – as said, not available at the time Orffer did his crossing – vindicated Orffer’s suspicion: Pontac played no role in Roobernet, and the Cabernet Sauvignon tune had all the time been backed up by Alicante Bouschet.

This was confirmed in 2007, a year before Orffer’s death, and in his letter to Vititec he stated that “pollen from Alicante Bouschet must therefore have entered inadvertently”.

Which, at the end of the day, makes Roobernet and Ukraine’s Odesa Black the same cultivar, the difference being that it was not a Stellenbosch, South Africa “discovery”, as Odesa Black had emerged far earlier.

The advent of DNA analysis also rewrote the origins of other grape varieties. Take the case of another esteemed viticulturist, Dr Hermann Müller of Thurgau in Switzerland, whose Riesling and Sylvaner crossing, named Müller-Thurgau, at one stage surpassed Riesling plantings in Germany. Some researchers later questioned this, as many characteristics corresponded almost exclusively with Riesling and not with Sylvaner. Under scrutiny of DNA analysis, Dr Müller’s famed variety was shown to be, in fact, a marrying of Riesling and the Madeleine Royale grape, with Sylvaner nowhere in sight.

Proving to us of a limited academic nature that even at the top echelons, science is not exact.