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Residual Sugar: What Is It and What Does It Indicate in Your Wine?


When wine tasting or buying wine, you may have become familiar with the term ‘Residual Sugar’. But what is it and what exactly does it indicate when it comes to wine?

Residual Sugar (RS) is the natural grape sugar leftovers in a wine after the fermentation finishes. According to Wine Folly, the sugar in grapes is a blend of glucose and fructose. While it is in the fermentation stage, yeast eats those sugars to make alcohol. Some winemakers choose to stop the fermentation before all the sugar is gone – which is one technique used to make sweet wine!

But, do wineries add sugar to their product? The answer is: some. Experts explain that there are some countries – like France and Germany – that do allow the addition of sugar before or during fermentation. This process is called “Chaptalization” and is used when the winemaker wants to increase the total alcohol level when under-ripe grapes are used. It is however not meant to be used to increase the sweetness of the wine.

Chaptalization is a wine additive process that is common in cool climate growing regions where sugar is added when grape brix levels (sugar content) aren’t high enough to produce the minimum alcohol level. It is illegal in the United States.

Sugar Level in Wine

The residual sugar level in wine varies in different styles of wine. Typically, dry and off-dry wines will have a residual sugar level between 1 and 11 grams per liter (g/L) of residual sugar. Sweet wines will start around 35 g/L and then go up from there.

(Infographic showing how many teaspoons of sugar per 5 oz glass of wine. Courtesy of Wine Folly.)

When the yeast is able to eat up all of the sugar during the winemaking process, the final result will be a product that is higher in alcohol content and lower in sugar, or a dry wine. When the yeast is stopped by a winemaker, the final product will have sugar that remains and a lower alcohol content, or a sweet wine.

This is why you may find many sweet wines to have less alcohol than dry wines. One example of this would be German Riesling. It has about 8-9% alcohol by volume (ABV) if it is sweet and 10-11% AB if it is dry.

Measuring Sugar in Wine

Usually, Residual Sugar is displayed in one of three ways: grams/Liter, grams/100ml, or as a percentage. An example would be 10 grams per liter of residual sugar is equal to 1% sweetness.

Depending on the style, wines will range from 0 to 220 grams per liter sugar, explains Wine Folly. Dry tasting wines will contain up to 10 grams of sugar per bottle. If you are a person that tracks calories, the break down of sugar calories for each style of wine goes as follows:

  • Bone-Dry <1 sugar calories per glass
  • Dry -6 sugar calories per glass
  • Off-Dry 6-21 sugar calories per glass
  • Sweet 21-72 sugar calories per glass
  • Very Sweet 72-130 sugar calories per glass

Most countries, including the United States, aren’t required to label actual sweetness levels in wine. Because of this, there is a very small chance you will find the sugar level listed on a physical bottle of wine. If you really want to know the level of sugar in the wine, you can check out the tech sheets on the winery’s website.

Sugar Level in Sparkling Wine

Does a glass of sparkling wine have less sugar than a glass of still red or white wine? According to Glass of Bubbly, Champagne and sparkling wine contain less calories than red and white wine. Red wine can contain around 100 kcal per glass while bubbly can contain around 80 kcal per glass. Usually, the most common dry sparkling wine styles contain half a teaspoon of sugar per glass.

During the winemaking process for sparkling wine, sugar is added to balance out the bitterness and give it a more rounded flavor. Below is a breakdown of each style of sparkling wine and its level of sweetness:

  • Brut Nature (also known as Brut Zero): 0-3 g/L residual sugar
  • Extra Brut: 06 g/L residual sugar
  • Brut: 0-12 g/L residual sugar
  • Extra Dry: 12-17 g/L residual sugar
  • Dry: 17-32 g/L residual sugar
  • Demi-Sec: 32-50 g/L residual sugar
  • Doux: 50+ g/L residual sugar

(In an attempt to show what Champagne sweetness really looks like, we filled each glass with the actual amount of granulated sugar (in grams). Courtesy of Wine Folly.)