Wines range from 0 to about 220 grams per liter sugar, depending on the style. Dry wines can contain up to about 10 grams of sugar per bottle but still taste dry.
Bone Dry less than 1 cal per glass
Dry 0-6 cal per glass
Off-Dry 6–21 cal per glass
Sweet 21–72 cal per glass
Very Sweet 72–130 cal per glass
The terms above are non-official and simply show a common range in still wines. Currently, most countries (including the US) aren’t required to label actual sweetness levels in wine.
Where Does Sugar in Wine Come From?
The sugar in wine is called residual sugar or RS. RS doesn’t come from corn syrup or granulated sugar like you might think, it primarily comes from the fruit sugars in wine grapes (fructose and glucose). Of course, there are a few instances where cheap wine producers will use sugar or grape concentrate to sweeten a wine–all the more reason to seek out quality!
How come some wines are dry and some are sweet?
Basically, when winemaking happens, yeast eats sugar and makes ethanol (alcohol) as a by-product. A dry wine is when the yeast eats all the sugars and a sweet wine is when the yeast is stopped (usually by chilling the fermentation) before it eats all the sugars. This is why some sweet wines have less alcohol that dry wines. A great example of this is German Riesling, which usually have about 8–9% ABV when sweet and 10–11% ABV when dry.
How Does One Determine the Residual Sugar in Wine?
The most accurate way to identify sweetness in wine is to look for a tech sheet about the wine in question. Many producers offer the technical notes on each vintage of their wine as a courtesy. RS is usually displayed in 1 of three ways: in grams/Liter, in grams/100ml, or as a percentage.
Why we suck at tasting residual sugar in wine
Exact levels of residual sugar are actually quite difficult to taste with our “naked tongue.” Even highly trained wine tasters often have trouble identifying RS in wine–but you can learn with practice. The main reason we can’t taste sweetness that well is because other traits in the wine, including the acidity level and tannin, distort our sensitivity to sweetness.
You can test this oddity yourself by tasting plain sugar and then tasting the same portion while biting into a lemon. The acidity will cancel out all or most of the sweetness on your tongue.
Several people requested a few real-world examples of red wines that contain residual sugar as examples. Here are a couple for historic reference only:
Alta Vista Classic Malbec (2013): 2.8 g/L
Gnarly Head Old Vine Zinfandel: 3.4 g/L
Menage a Trois California Red: 12 g/L
Yellow Tail Shiraz: 12 g/L
Apothic Red: 15 g/L
Jam Jar Sweet Shiraz: 57 g/L
What if there’s no information about a wine?
If you can’t find a technical sheet, or if the RS is not listed, here are a few tips:
Cheap wine usually has residual sugar. It’s safe to assume that most affordable (sub-$10) wines from the US contain some residual sugar, perhaps anywhere from 2–15 g/L. There are, of course, excellent exceptions to this rule so look for more information first.
Buy better wine. If you spend a little more on a bottle of wine, say around $15–20, producers tend to feature less residual sugar (if any at all). Grapes are higher quality so the wines don’t need sweetness to taste fruity.
Drink less. Even at 15 g/L RS, a wine will only add about 7.5 sugar calories. Like with all things, your best bet might just be moderation.