Peter Lehmann Margaret Barossa Semillon 2005

Top Aussie Sem. And it's not from Hunter Valley...

On Friday, a workshop conducted by Steenberg winemaker JD Pretorius towards a better understanding of Semillon. At the end of 2010, it was the 12^th most planted variety in the country with the total area amounting to 1 182.4ha (some 30% of this is planted in the Breedekloof where it’s used to dolly up entry-level white blends).

In South Africa, there are two basic styles. Firstly, there are those with high methoxypyrazine counts (compound providing herbaceous aromas and flavours) and for such a wine look no further than the David Nieuwoudt Ghost Corner from Elim. This is a controversial expression of the grape and whether you will like it or not depends very much on your tolerance for that “green” character. Much speculation about how these wines age with some contending that they soften and complexify, but my experience being rather that the best remain remarkably primary and the worst degenerate, becoming thick and soupy.

Secondly, there are those that have had some oak treatment and take on a more weighty texture with time in bottle. Here Boekenhoutskloof in Franschhoek leads the way. The wine is typically matured in 100% new French oak for 13 months, but at very low temperatures to keep oak extraction to a minimum. The 2008 tasted during the workshop showed great fruit concentration, the oak noticeable but very much part of the wine. Still two or three years off its best.

Constantia Semillon will perhaps always have the broadest appeal, the cooler climate growing conditions producing some but not excessive green character while a degree of oak treatment lends richness and texture. I thought the Steenberg 2007 (closed under cork) was all of a piece and had the edge on the Uitsig 2007 (screwcap) which was still coming around; meanwhile the Steenberg 2005 (also under cork) appeared unduly advanced relative to the Uitsig 2005 (screwcap).

By way of intrigue, Pretorious included Peter Lehmann Margaret Barossa Semillon 2005 in the line-up. Following a two-week fermentation period, the wine is bottled immediately and then cellared at the winery before being released as a five-year-old wine. Great fruit concentration offset by fresh but not seering acidity (abv 11.5%, RS 5.95 g/l, TA 7.38g/l, pH 3.03).

An overall impression arising out of the tasting is that single-variety Semillon is destined mainly to be the pursuit of wine-geeks. Pyriazine-driven Sem is a döppelganger for Sauvingon Blanc and so you could ask “what’s the point?” while those that have had some oak treatment are typically more about texture than overt aromatics and flavours.

An attribute of Semillon is that while it is low in pH, it is also generally low in acidity (contrary to the norm where a low pH typically corresponds to a high acidity). Clearly, the best examples can age, but they do tend to become a little ponderous. Vinifying it alongside Sauvignon Blanc to add a little verve is surely the way forward.