Nutritionists call it "invisible sugar", that phenomenon of modern life that has seen sugar in its various forms creep into just about every packaged food. It's not just that can of full-fat Coke; it's the cheeky addition to the packet of crisps, the pasta sauce, the slice of bread.
You might have thought the wine industry was moving in the opposite direction. After all, over the same period that Big Food has been feeding us high fructose corn-syrup, sweet wine, the most popular style right up to the Blue Nun and QC-flavoured 1970s, has fallen from favour. We've come to think of dry wines as synonymous with quality and sophistication, and sweeter options as wine for beginners – the sugar acting like stabilisers until we get used to sourness and tannin.
In fact, sugar in wine never really went away, it just had to get sneaky. Most people, in a phrase occasionally used by the wine trade, "talk dry, but drink sweet", and brand owners have had to learn ways of getting round this conflicted behaviour. That's why many of the biggest-selling wines, while avoiding the words "sweet" or "sugar" on the label and being packaged like dry wines, contain quite a bit of sugar. This is particularly true of Californian brands such as Blossom Hill and Echo Falls and Australians such as Yellow Tail, whose reds and whites will often smuggle in 10 grams or more of residual sugar per litre, appreciably more than the 1-2 grams in the average red Bordeaux .
But it's not just obviously mass-market wines that have more sugar than you might expect. Preparing to write this column, I had a look back through the technical data given out by retailers and wineries at various tastings over the past year, and I was surprised by how many supposedly "dry" New World and southern European reds come in at 6g/l or more, and how many whites at 8g/l or more.
The problem here isn't the level of sugar itself. The statistics are a bit of a red herring since there is more to the perception of sweetness in wine than sugar. Acidity, tannin and alcohol also play their part, with higher acidity making a wine taste less sweet, prominent tannin giving a feeling of dryness and higher alcohol giving an impression of greater sweetness. A wine with 2 g/l of sugar but low acidity and 15% alcohol may well taste sweeter than a high-acid wine of 10 g/l of sugar and 11% alcohol. It's all a question of balance.
Just as you don't really notice the individual instruments on a conscious level when you're carried away by a piece of music,- in the best wines you're not thinking about the sweetness levels, or the acidity, or the tannin. There's a harmony between all those basic elements that leaves you to focus on the allusive flavours and textures. The best sweeter wines – whether they have around 10 g/l of sugar like some of my favourite Alsace whites or more than 400g/l as in some Pedro Ximenez sherries – have that every bit as much as the best dry wines. Wines on varying degrees of the sweetness spectrum also do a much better job of matching spicy food: they're the only ones that really work with desserts, and are often fabulous with cheese. Where sugar does become a problem is when it's used to smooth over rough edges (spiky acidity, rasping tannin) or plug gaps (lack of fruit or body). The winemaker ratchets up the sugar, either by stopping the fermentation while there's still plenty of sugar left in the must (juice), or by adding sweetening agents such as concentrated grape must once fermentation is finished.
Just as tricky is the fact that you never really know how much sugar you're getting. The best you can expect is one of those vague, subjective sweetness scales offered by some supermarkets on their back labels. I think it's time that changed. Not just so we can have some idea how a wine might taste, but to bring this sneaky form of invisible sugar out into the open.
Six best sweet wines
Château Jolys Cuvée Jean Jurançon
France 2010
£14.49, Waitrose)
Deep in Pyrenean south-west France, Jurançon produces some of my favourite fully sweet wines from, in this case, late-harvested and wind-dried petit manseng, a swirling blend of candied tropical and orange fruit and mountain-fresh acidity.
STAR BUY
Ostler Blue House Pinot Gris Waitaki Valley, New Zealand 2010
(£18.50, Berry Bros & Rudd)
In pinot grigio (Italian for pinot gris) mode, this grape variety tends to be anonymously light and dry. When allowed to fully ripen and carry a bit of extra weight and sugar in Alsace or New Zealand, it's transformed into something much richer and more attractive, shimmering with quince and spice.
Tesco Finest Alsace Gewurztraminer
France 2012
(£7.99, Tesco)
Gewurztraminer's sheer force of unbridled musky perfume is at its best with a little sugar; really dry styles generally seem to miss out on its divisive flamboyance. This one has 14 g/l and is exotic like really good Turkish delight.
Joh Jos Prüm Riesling Kabinett
Mosel, Germany 2011
(£15.95, Corney & Barrow)
The classic racy, delicately lacy off-dry style of German riesling is becoming increasingly rare: the Germans are these days much keener on dry wines. J J Prüm have remained masters of the style, however, and this is a dancing, joyous low-alcohol white.
Allegrini Palazzo della Torre Veneto,
Italy 2009
(from £14.99, Imbibros.co.uk; Roberson; Tesco; Wine Direct; Rannoch Scott)
Most of the world's better red wines are properly dry, but the use of some dried grapes, which naturally concentrates the sugars, brings a bittersweet-tinge to the cherries and dark chocolate in this lighter but still sumptuous take on Amarone from northeastern Italy.
Domaine des Aubuisères Cuvée de Perruches Vouvray
Loire, France 2012
(£9.99, or £8.99 if you buy two bottles, Majestic)
Like riesling, chenin blanc is made into every conceivable level of sweetness in the Loire, from bone dry to lusciously sweet. This is off-dry (9 grams of sugar), but its brisk apple-store character would be so good with pork chops.
