NOT all wines taste moreish, unless thirst or the desire to adjust your blood alcohol level assume more importance than your sense of appetite. The quality in a wine that makes the urge to consume overwhelm your ability to resist temptation is often called "savouriness" by wine tasters — but it is as hard to define as it is to encounter. Tartness is certainly an element, although not all wines with marked acidity invite you to consider a second glass, and not all high-pH wines dull the appetite.

Sugar, even for those with a sweet tooth, doesn’t always drive consumption, and when it presents as viscosity on the palate, it can actively discourage any further interest.

The same is true for tannin — a little appears to add spice to texture, while overly dense wines, which may taste striking when presented to a judging panel, stop those who actually drink (rather than sample) at the first half of the glass.

Wine makers are often neglectful of the need to make wines appetising, concentrating instead on elements such as "showiness" — presumably with an eye on competition triumphs and high ratings. One of the most frequent criticisms of US über-guru Robert Parker is that his aesthetic criteria have driven producers in the direction of palate weight and excess, rather than elegance and nuance.

There can be little doubt that showiness — while it helps to draw attention to a producer or an estate — is not the quality that drives consumption in the long term. The success of Sauvignon Blanc over Chardonnay as a category reflects the views of wine drinkers rather than critics. Wine experts are largely in agreement that the best Chardonnays are infinitely more complex, and have greater potential, than the best Sauvignons. However, if you look at restaurant tables, Sauvignon outsells Chardonnay by three to one.

At a recent tasting — where an array of mostly white wines was presented — I pondered the question of savouriness as I tasted a line-up of a number of white varieties, as well as a few Pinot Noirs. The wines ranged from R25 a bottle to R200, and across the sweetness spectrum from diabetes-inducing to bone dry. The Rieslings, despite generally more overt sugar than any other category, were clearly food-friendly in their own right, and also attractive as aperitifs.

The best of the class was the Dewetshof 2009, followed by the Paul Cluver 2010. The Gewurztraminers, though generally drier than the Rieslings, were no more savoury as a result: perhaps it’s the pungency of the fruit, the more vegetal earthiness, that makes the average Gewurztraminer seem less moreish. Only a couple matched the savouriness of the Rieslings, with the Zevenwacht 2011 being the best.

A Bukettraube from Cederberg did nothing to change my view about the variety, nor did it offer an alternative to the aperitif quality of Riesling. The large class of Chardonnays came with a wide range of styles but, even here, it wasn’t always easy to predict which wines would make the bottom half of the glass as interesting as the first sip. True, the Rustenberg unwooded Chardonnay 2010 had the same savoury quality we have come to expect of Sauvignon Blanc, but the carefully oaked Glenelly 2011 (curiously, from a property right next door to Rustenberg) was as attractive — and also more complex.

At the end of the day, there were four lonely Pinots, bringing the prospect of at least a little tannin to contribute to the discussion about freshness on the palate. The best was the regular Bouchard Finlayson Galpin Peak 2011, with the faintest of green edges to its black cherry fruit, and a lovely integration of (almost absent) oak. It was infinitely more moreish than the dramatically more expensive reserve wine from the same cellar — the Tête de Cuvée — suggesting that savouriness is the quality you encounter in the absence of too much of a good thing.