South Africa's apartheid system and the protest embargoes which isolated the country from the rest of the world helped to preserve its rich stock of old vines, a leading producer claims.

"When we came out of sanctions, South Africa sat back and we realized that although we might have seen ourselves as being 'behind,' this had probably all been good in the artificial preservation of the country and its old vineyards,” said Eben Sadie of Sadie Family Wines at the Cape Wine 2012 convention in Cape Town.

The country's oldest still-producing vineyards were planted between 1882 and 1890, and there are at least 300 sites that are more than 35 years old. As a result, South Africa is now gaining an international reputation for producing interesting, high-quality wines from these mature vines.

“In some respects, in a paradoxical way, sanctions kept this country back from the renewal, replanting new clones, new strains, all of that. In a way they preserved South Africa,” Sadie observed.

Viticulturist Rosa Kruger suggests other reasons for the survival of the country's stock of old vines, including sentiment, the prohibitive costs of removing the vines, and the fact that they were prized for producing high-quality grapes. It has also been noted that many of the country's old vines grow in a polyculture alongside other plant life, which may have inhibited diseases.

“Most of our old vines are planted in remote areas where a farmer supplements his income with rooibos [tea] or proteas [South Africa's symbolic flower],” said Kruger. “Many are planted among the fynbos [natural vegetation] so there is much less disease pressure, natural predators and no spread of leaf roll.”

The country is now keen to promote its old-vine wines. However, old vines tend to produce small quantities of fruit each year compared to young, vigorous vines and this presents a problem. South Africa's reputation for producing well-priced wines could make it hard for growers with old vines to earn a living, possibly endangering the old-vine heritage.

Sadie explained: “If the world only sees out of South Africa value-for-money £3.99 [$6.50] wines, we are going to have great difficulty to keep this dynamic going. It's like everybody wants to eat natural but when they have to pay more for the tomato, they'd rather go for the chemical one. We need a new logic.”