Diemersdal Estate from Durbanville has received the first international accolade for its revolutionary Winter Ferment Sauvignon Blanc, winning a Gold medal at the Concours Mondial du Sauvignon held this year in Udine in Italy‘s Friuli region. Diemersdal Winter Ferment 2018, the farm’s second vintage of this specific wine style, was one of six South African wines to win Gold at this year’s competition, which drew 1 010 entries from 36 countries.

Diemersdal Winter Ferment is made using an innovative wine-making process where the Sauvignon Blanc juice is frozen during the harvest in February and then thawed five months later, after which it is fermented to produce a wine with exceptional tropical flavours.

“Concours Mondial du Sauvignon offers the pinnacle of recognition for Sauvignon Blanc as the competition is focussed on this variety at an international level,” says Thys Louw, Diemersdal’s owner-winemaker. “Although Diemersdal was fortunate enough to win two Gold medals at last year’s show, we are really pleased at this year’s Gold going to our unique style of Sauvignon Blanc. It began as an experiment, but after only two vintages the Winter Ferment is proving to be one of the most lauded wine in Diemersdal’s Sauvignon Blanc offering.”

The Winter Ferment has, among other awards, appeared on the FNB Top 10 Sauvignon Blanc list in 2017 and 2018.

The Diemersdal Winter Ferment Sauvignon Blanc 2018 was made by freezing the grape must to -20°C soon after the grapes were harvested in February. The frozen must was thawed in June last year, inoculated and allowed to ferment as per normal, resulting in a wine of extraordinary tropical profile.

“The primary feature is the high occurrence of thiol compounds in the wine,” says Louw. “These thiols are what gives Sauvignon Blanc the passion fruit and goose-berry flavours for which especially the wines from New Zealand have become famous for.”

Louw says that while a high thiol count for a tropical style of South African Sauvignon Blanc amounts to 2 500 nanogram per litre, the Winter Ferment Sauvignon Blanc measures in the region of 5 000 nanogram.

“This high thiol level is unheard of in South Africa and is more in line with what one would find in wines from Marlborough, New Zealand,” he says. “When I set out with the idea of freezing must, I wanted to see what the effect would be on the freshness and complexity of the wine, including a possible increase in thiols. But no way did I expect the frozen juice to deliver a wine with double the thiol level we at Diemersdal had become accustomed to and with such extraordinary tropical flavours.”

The grapes for the Winter Ferment were night-harvested at 23B, with crushing and destemming done reductively. Skin contact of three hours was followed by pressing and the juice was allowed to settle for 48 hours after which it was frozen. The fermentation of this wine was postponed for four months before inoculated with CKS yeast. After two weeks alcoholic fermentation at 14-16oC the wine was bottled.

Louw describes the wine as the most “new world style of Sauvignon Blanc” he has made. “The wine has intense aromas of gooseberries, tropical fruit and sweet-grapefruit with a core of minerality. Besides the intense fruit-expression, the excellent natural acidity creates balance to the concentrated, rich mouth-filling texture.”

Louw says the Concours du Sauvignon continues to grow in importance due to the commercial success of Sauvignon Blanc throughout the world.

“The reason the consumer likes the variety, is because it is easy to understand,” says Louw. “When buying a bottle of Sauvignon Blanc, whether it costs R60 or R600, there is going to be an element in that wine to which the wine drinker can relate, something in the flavour profile he or she can understand… freshness, balance between fruit and acidity, a pleasure to drink.”

Louw says that that Sauvignon Blanc also has the potential to make major inroads for South African wine into export markets, especially the sought-after American market.

“The global demand for and awareness of Sauvignon Blanc is at an all-time high,” he says. “In South Africa Sauvignon Blanc outsells other white varieties three-to-one. Already South Africa exports over 20m litres of Sauvignon Blanc in packaged form, and with our recognition for world-class Sauvignon Blanc growing, we have the chance to increase this exponentially and make real global mark – not only for Sauvignon Blanc, but also for Brand South Africa.”