Boschendal wine estate, probably one of the most picturesque wine estates in South Africa (and the world for that matter) produces three different Sauvignon blancs. With all three of these wines they try to achieve (and succeed if you ask my opinion) a more international / European style Sauvignon. They achieve this style by simply altering their fermentation conditions. As simple as that.
The grapes are picked on taste between 20.5 – 22°Brix. The rule is that all Sauvignon blanc grapes must be in the cellar by 12 noon to avoid the heat of the day. Winemaker, Lizelle Gerber, then adds the Laffort skin contact enzyme after which the grapes go through a mash cooler to cool them down to between 9 – 14°C. Skin contact is for 4 hours and not all grapes get deliberate skin contact. Some of the grapes only have “skin contact” the time it takes to fill the press. After pressing the juice settle for 48 hours at 10 – 12°C with an addition of Laffort settling enzyme. The juice is then racked and fine lees incorporated to achieve a final NTU of 130 on average. This is a big difference compared to the previous two producers mentioned in previous blog entries who aim for a final NTU of 50 – 80. The latter is more suitable for new world style wines and the 130 NTU is more in line with the NTU levels obtained in Europe. The reason for the 130 NTU objective is that it suits the yeast – Laffort VL3 better and it is better for mouthfeel development. According to Lizelle, mouthfeel is their main objective before aroma. In the case of typical new world wine production, aroma is usually the first objective and by decreasing NTU and fermentation temperature it helps one to achieve this objective.
After inoculation of the yeast the temperature rises to about 18°C and it is kept on average at about 17°C throughout fermentation. Once again this is a requirement of the yeast and is also different to the practices of the previous two producers who conducted fermentation at much lower temperatures. Boschendal does analyse for YAN before fermentation and do adjustments accordingly during fermentation. They use Lallemand Fermaid K (Laffort probably ran out of stock since they seem to like Laffort) and liquid ammonia – permitted in South Africa. Fermentation lasts between 14 – 18 days. VL3 is used mainly for its mouthfeel and tropical aroma contribution. Boschendal is not interested in emphasizing any pyrazine aromas typically associated with South African and New Zealand Sauvignon blancs.
The wines are kept on the gross lees for as long as the lees are healthy. After the blends are made up the wine is kept on the fine lees until stabilisation before bottling. Bottling is done on demand and usually starts in September of the same year.  The single vineyard reserve is kept on the lees longer and bottled much later.
The Boschendal Sauvignon blanc is a typical example of how altering your fermentation conditions can influence your wine style. It does not mean that you will all of a sudden produce a Sancerre because you ferment like Sancerre (I’m not sure how winemakers ferment in Sancerre but I suspect it is not with new world wine yeasts at 13°C). The terroir is still completely different. It does however give you a style of wine that is more appealing to the European palate but with a flair of new world freshness.