If you know a more catchy slogan than "variety is in our nature", you should be in wine marketing. This is the soundbite promoting the wines of South Africa (varietyisinournature.com) as a reflection of the country's "unique biodiversity". By convincingly linking the Cape's floral kingdom to its diverse soils and climates, it cheekily borrows the mantle of terroir from the French, who coined wine's currently most overused term in the first place. But do thousands of plant species combine with ancient soils, ocean breezes and rugged landscapes to make wine "of character and quality"?

Possibly, but not without a helping hand. The reality is that the influence of terroir in wine is as much the result of human endeavour as outside influence. In the case of the Cape, those individuals best able to interpret their vineyards' potential are making the best wines. But as with any generic marketing set-up, to trumpet the virtues of variety and quality is a convenient way of avoiding biting the hand that feeds it.

If this all sounds somewhat curmudgeonly, the variety issue was put to the test at a tasting of a range of Cape wines at the South African High Commission in London last month.

Sauvignon blanc showed that it's gone from great white hope to great white reality. Andrew Gunn's pungently herbal and mouthwateringly crisp 2010 Iona Sauvignon Blanc, £9.99, Waitrose, Majestic (buying 2) stood out, along with the consistent, nettle-fresh, green peppery 2010 Springfield Life from Stone, £8.95, The Wine Society, a pristine, almost sancerre-like 2010 Ataraxia Sauvignon Blanc, £10.75-£11.95, Stone, Vine & Sun (01962 712351), Jeroboams shops, and juicy, gooseberryish 2010 Crow's Fountain Traditional Bush Vine Sauvignon Blanc, £9.99, buy 6 = £7.49, Marks & Spencer.

Chenin blanc remains a Cape trump card and while Bruwer Raats is among the best exponents with his fragrantly exotic 2010 Raats Original Chenin Blanc, around £9.49, Handford (020-7589 6113), Vinology (01789 264586), Bellingham's 2010 The Bernard Series, £9.99, Majestic is impressively opulent with its honeyed appley flavours, while Sainsbury's Taste the Difference Fairtrade Chenin Blanc, £7.99, tingles with refreshingly peachy fruit. Chardonnay put its best foot forward with an elegantly butterscotchy, burgundian-style 2009 Delaire Chardonnay, £73, 6-bottle case, Justerini & Brooks (020-7484 6400) and the exciting new-wave Rhône-style blends from Swartland in the complex, stonefruit and apple qualities of the 2009 Mullineux White Blend, £15.95, Berry Bros & Rudd (0800 280 2440).

There isn't enough space this week to explore the reds in depth, but it would be fair to say that with a combination of Bordeaux blends, Rhône-styles syrahs, emerging pinot noirs, and, er, pinotages, they, too, are looking more exciting then ever. Examples worthy of note included a modern Cape claret-like red in the 2008 Vergelegen Premium Cabernet Merlot, £10.39-£10.99, Morrisons, Majestic (buy 2 = £8.79), a convincingly Rhône-like spicy and succulently dark-fruited 2007 Newton Johnson Syrah Mourvèdre, £13.49-£14.29, slurp.co.uk, Wholefoods, sawinesonline, and a stylish Cape-meets-Pauillac 2007 Grand Vin de Glenelly, £16.75, Jeroboams. Variety in South Africa's nature? Maybe there is something in it after all.