"The vineyard practices and approach to Sauvignon Blanc in the wineries and the local wine community’s united focus on the variety, got under my skin. I began toying with the idea of offering South African consumers a taste of Marlborough’s pungent, expressive Sauvignon Blanc under a Diemersdal label."
At the beginning of 2019, Louw found himself back in Marlborough as the South African representative at the annual Marlborough Celebration of Sauvignon Blanc, an international conference focussing on the cultivar. And outside of the formal duties, Louw teamed-up with local winemaker Ben Glover from Glover Family Vineyards to initiate Project Diemersdal Marlborough Sauvignon Blanc.
Ben Glover and Thys Louw
"Marlborough has over 20,000ha of Sauvignon Blanc planted to a diversity of terroir, but I knew where I wanted the grapes for my wine to come from. This was from the Dillons Point sub-region, an area that produces some of the finest Sauvignon Blancs in New Zealand and from where Glover Family Vineyards accesses some of its fruit," says Louw.
Mild summers, cold winters and substantial variation in day-and-night temperatures make Marlborough an ideal region to ripen Sauvignon Blanc grapes with high levels of thiols, compounds leading to the tropical notes of gooseberry and passion-fruit so typical of the region’s wines. Soils are stony sandy loam over very deep, stony gravels.
While Louw was back at Diemersdal attending to his own harvest season, Glover picked the grapes for Diemersdal Marlborough Sauvignon Blanc at the end of March.
The must and juice were handled anaerobically to protect against any potential oxidation and to maintain juice freshness.
The juice was co-fermented with a combination of yeasts to enhance some of the characteristic thiol notes, but to maintain the vibrant ripe herbaceous notes of the vineyard. Average time for fermentation was two weeks at between 12°-13° deg C – the aim being to drop 1.5° balling a day.
The wine was left on gross yeast lees for another three to four weeks before racking into a tank with some of the lighter lees. Tanks are stirred weekly for texture and mouth-feel. The wine was lightly fined to polish and stabilise before bottling, which was done in August.
Louw says the final results are exactly what he was looking for. "The Dillons Point area of Marlborough is renowned for producing stunning pungent wines of power, finesse and vibrancy. And you find it in our Diemersdal Marlborough Sauvignon Blanc, those characteristic tropical notes of granadilla, gooseberry and Kiwi-fruit, all harnessed by a firm, bracing freshness.
"This is one of the aspects about Marlborough that truly stands-out: no matter where you are, no matter what the name of the producer reads on the bottle, if you taste a wine made in that part of the world, you know you are tasting Marlborough Sauvignon Blanc. And for Diemersdal it is a great honour to be able to present this to South African wine drinkers who have already made Sauvignon Blanc the country’s most popular varietal wine."