How Sweet It Is
Sugar vs. alcohol
Sweetness — or lack of it — is fundamental to the wine-tasting experience; in fact, without sugar, there would be no wine.
During the process of fermentation, yeasts convert the natural sugars in wine grapes into alcohol. As alcohol levels rise, the yeasts die and fermentation stops. Leftover sugar that has not been converted is known as “residual sugar.” Generally, the higher the natural sugar level of the grape, the higher the alcohol in the resulting wine; and the higher the level of residual sugar, the lower the level of alcohol. So low-residual sugar wines like California Cabernet or Argentinian Malbec have more alcohol by volume than a high-residual sugar German Riesling or Italian Moscato. Wines with low residual sugar are said to be “dry,” while those with high residual sugar are “sweet.” Anything in the middle is “off-dry.” Most reds and many whites and sparkling wines are dry; some whites and the majority of rosé wines are off-dry. Dessert and late-
harvest wines are sweet.
Balance is of critical importance. Winemakers work hard to manage the relationship between residual sugar and acidity, alcohol, and tannins (all three of which affect the perception of sweetness). A high-sugar wine unbalanced by proper acidity tastes overly sweet and “flabby.” But the perception of residual sugar is not always straightforward: a California Zinfandel or an Australian Shiraz can taste quite fruit-forward or even jammy, giving the impression of sweetness, when these wines are in fact quite dry. High levels of acid or tannin can mask the sweetness of high-residual sugar wines.
Not all sweetness occurs naturally. Vintners sometimes raise residual sugar levels by artificially stopping fermentation early, thus lowering alcohol conversion. A somewhat controversial practice known as “chapitalization” (or enrichment) allows winemakers to add cane sugar or grape concentrate to the unfermented grape "must" (the skins, seeds and stems in the freshly squashed fruit). This increases the production of alcohol.
Chapitalization is more common in cooler growing regions where grapes ripen slowly and so produce less natural sugars, such as France, Germany and Oregon, but it is not permitted in Argentina, Australia, Italy, Spain and California.
EXPERT WINE RECOMMENDATIONS
• John Hutzler
Vino e Birra 18 W Burlington Ave., La Grange (708 639-4466)
- 2015 Illusion Red Blend (Calif.) $17. Based on old-vine Zinfandel, this blend from Lodi offers a nose and palate of black currants, plums and chocolate. Tannins are soft and the finish is lingering.
- 2015 Peirano Estate Chardonnay (Calif.) $17. Aromas of peaches, melons and apples precede a palate of apples, pears, peaches, and tropical fruit, all complemented by hints of vanilla, butter, and hazelnut.
• Simon Lambert
The Chicago Wine Co. 835 N Central Ave., Wood Dale (630 594-2972)
- 2013 HdV Hyde Vineyard Chardonnay (Calif.) $63. A fresh, clean nose of peaches, apples, and citrus blossom is echoed on the palate where notes of cream merge with a flinty minerality. A beautiful acidity brings balance and depth.
- 2010 Chateau Lafleur-Gazin (France) $37. From Pomerol, a blend of Merlot and Cabernet Franc exhibits enticing aromas and flavors of raspberries, cherries, plums, chocolate and mocha. The mouthfeel is fruit-forward, with fine, nicely integrated tannins and a long oaky finish.