One lump or two? The question of sugar in wine

We think dry but drink sweet. Many of us have a prejudice against anything sweet in wine, although we are quite happy to drink sugary soft drinks. Yet a percentage of the so-called dry wines, including some red wines, on our supermarket shelves are actually off-dry or medium-dry. It can be unfermented sugars from the grapes, or rectified grape must added after fermentation, although adding sugar to a fermenting wine, as practised in cooler parts of Europe, does not add to the sweetness of a wine, as it ferments into alcohol.

Residual sugar is measured in grams per litre. It is not possible to ferment wines to absolute full dryness, but most of the great red and white wines of Europe will have levels of  less than 2 grams per litre.  Our perception of sweetness depends on the level of acidity. The higher the acidity, the less sweet a wine tastes, even with relatively high levels of sugar. Most German Trocken (which means dry in German) have levels going from 4g/l to 12g/l. The big Champagne brands will typically have around 12 g/l, barely noticeable with the high levels of acidity.

In recent years larger producers in the New World and increasingly in Europe have started leaving anything from 3-8 g/l to round out the flavours. If you have grapes that is naturally high in acidity, a few grams of residual sugar will make the wine more palatable to a wider audience. Examples include New Zealand Sauvignon Blanc, Côtes de Gascogne and less expensive Italian white wines. The Marks & Spencer Sicilian Grillio has 6.8 g/l of residual sugar. The wine doesn’t taste particularly sweet. Many medium-priced Californian wines, red and white, have higher high levels.

With red wines, the most obvious example are Ripasso and passimento wines. The Pasqua Passimento, currently available in retailers around the country, has 16 g/l residual sugar. To me it tastes like a sweet wine.  The Zenato Ripassa has 18 g/l. yet seems drier. Are these wines half way to Port? Not quite – Port has anything from 80 – 130 g/l.

Is all this sugar a bad thing? At the less expensive end, it rounds out any rough edges or harsh acidity, but I find it sometimes muffles the flavour, leaving a bland, slightly confected wine. And how do you know? At their press tastings, Marks & Spencer helpfully list the acidity, ph and residual sugar of each wine, although it does not appear on the label. Some importers, such as Liberty Wines, show it on some wines on their website. The LCBO, the Liquor Control Board of Ontario, and other Canadian state-run monopolies for all alcohol now helpfully list it for most wines on their website.

Sweet wines are different matter. They can have levels going from 80 g/l. (still less than most soft drinks, smoothies and juices) up to a whopping 400 g/l in the case of a Pedro Ximénez sherry.