How Much Sugar is in Your Wine?

You can find sugar in everything from soda to yogurt to ketchup. But what about in your wine? The topic of sugar in wine is often misunderstood. The truth is, there are so many different styles and wine regions that determine the sugar levels in your wine. To complicate matters, there is no requirement to disclose sugar levels on wine labels.

The good news is that one of the most popular styles of wine—dry wine—happens to be the style with the lowest sugar levels. Even then, we need to understand a little bit about the role that sugar plays in winemaking so you can determine which wines have low sugar levels and which ones to steer clear of. There are plenty of wines that are very low in sugar and it’s not uncommon in the natural wine world to find wines with sugars as close to 0 as possible. However, there are some instances where even a wine labeled dry may actually have far more sugar than expected.

This guide is designed to tell you everything you need to know about the role that sugar plays in wine, and how to find the best option for you.

How much sugar is in wine?

Sugar in wine is not a straightforward topic. Wine varies from place to place, and from year to year. And wine simply wouldn’t exist without sugar; it plays a central role in the making of wine.

But in general, a 5-ounce pour of dry wine contains 0-1.5 grams of residual sugar. Let’s look at the varying styles of wine and their residual sugar levels.

Dry Wine: 0 – 1.5 grams per glass

Off-dry Wine: 1.5 – 5 grams per glass

Sweet Wine: 5 – 6.7 grams per glass

Dessert Wine: 6.7 – 14.8 grams per glass

That’s a pretty big range! To keep your sugar intake low, we are often told to opt for dry wine styles, and even ask for “bone-dry” when shopping or dining. However, what is often overlooked is that Residual Sugar is not the same as Total Sugars.

Understanding Residual Sugar

When referring to sugar in wine, you’ll often hear wine professionals refer to the residual sugar (RS) levels. Residual sugars refer to natural sugars that are left over when fermentation either naturally completes or is halted by the winemaker.

The main process of making wine is fermentation. During fermentation, yeast is introduced to a barrel of crushed grapes. The yeast eats the sugars contained in the grapes and converts them to alcohol. As this goes on, the sugar level drops and the alcohol level rises.

There’s another important role that sugar plays in wine. The flavor compounds are bound up in the sugar, and during fermentation, they are released. So not only does the alcohol come from sugar, but so do all of those interesting flavors in your glass of wine.

The irony of the life cycle of yeast is that even though it creates the alcohol, it can’t survive once the wine reaches about 15% ABV. If the grapes have high sugar levels to begin with, this means that the yeast will die before it can finish converting all of the sugar to alcohol.

What is left is residual sugar.

Sometimes, a winemaker will halt the fermentation process before the yeast can “ferment to dryness” because they want to leave a sweet profile to their wine. These wines are off-dry or sweet, depending on their residual sugar levels.

Residual Sugars vs. Total Sugars

Residual sugars might be a new concept to you, but total sugars aren’t. Total sugars are how all other food products are measured and labeled. To understand the difference between residual and total sugars, let’s look at the kinds of sugars you’ll find in wine. As you’ll see, there are fermentable sugars and unfermentable sugars in wine.

Glucose and Fructose

Glucose and fructose are fermentable sugars in grapes. These are the sugars that the yeast scavenges and converts to alcohol. The remaining residual sugar measures glucose and fructose levels.

Sucrose

Sucrose is an unfermentable sugar. Sometimes, this sugar is added to wine in a process called chaptalization. Most regions that allow for chaptalization (and some don’t) require that the sugar be converted to alcohol. The remaining sucrose levels are often very low, resulting in trace amounts.

Pentose

Pentose is another unfermentable sugar that is included in total sugar measurements, but not residual sugar. Pentose is often used by lactic acid during fermentation and doesn’t contribute to sweetness. It is often found in trace amounts as well.

Total sugars measure, well, the total sugars contained in the wine. So any sucrose or other sugar molecules like pentose will be taken into account. Testing for total sugars often happens for export purposes. Residual Sugars is always a lower measure of sugar than Total Sugars. By our measurement on average 1.4 grams per liter. When broken into 5 oz servings this is not a significant difference however, when sugar additions are made it can be.

Is sugar added to wine?

The process of adding sugar to wine is called chaptalization. It is sometimes practiced in regions that are too cold and don’t allow grapes to ripen enough sugar to make alcohol. They often use cane sugar or beet sugar to support the yeast in completing fermentation. In some regions, chaptalization is banned. In others, it is allowed as long as the sugar added is fermented completely.

In sparkling wine, a final dose of sugar is sometimes added to balance the acidity and achieve a level of dryness or sweetness. This is a traditional last step in the making of champagne and it’s called dosage. During dosage, a mixture of sugar and wine is added to the bottle of champagne before sealing with a cork.

In some places like California where dosage is not legal, a juice mixture containing fructose and glucose is often added instead.

Additionally, there are instances when sugar is added after fermentation is completed in which case the wine may be labeled as “Dry” even when total sugars may be significantly higher per serving.

Do some grapes have more sugar than others?

The grape varietal isn’t an indication of how much sugar is in your wine. For example, Riesling, known for being sweet, is actually a very versatile grape and is often fermented to dryness to make savory, aromatic dry wine. You can also find some really delicious sweet Riesling with lots of residual sugar. These off-dry and sweet styles make a great pairing to spicy food, flavor-forward food, and stinky cheeses.

The sugar levels, instead, are a result of three interrelated factors:

Climate

The type of climate determines how much sugar develops in the grape. Warm climates typically have long ripening seasons (read: summers) and more sun exposure, and that means higher sugar levels in the grapes. Cool climates, on the other hand, have cooler summers, shorter summers, and cloudier days. All of these factors lead to the grape developing lower sugar levels.

Harvest Time

The amount of time the winemaker lets the grape ripen on the vine is called “hang time.” The longer grapes hang on the vine, the more sugars they develop. As grapes hang on the vine, they’re also developing their signature flavors, softening tannins and green, unripe notes, and lowering in acidity.

The time at which a winemaker harvests is very precise and must be done when all of these factors, including sugar levels, are in balance.

Fermentation Duration

Once the grapes are harvested, it’s time to bring them to the winery, put them in a vessel and let them begin fermenting. A winemaker can choose to let the yeast “ferment to dryness.” This means that they let the yeast continue to ferment until all of the sugar has been converted to alcohol. This results in a bone-dry wine with higher alcohol and lower sugar levels.

Or the winemaker might stop fermentation at a certain point to keep a touch of sweetness in the wine. Last, the yeast might die before it can complete fermenting all of the sugar in the grapes. This is more likely to happen in warmer climates where sugar levels are higher to begin with.

Can you have a sugar-free wine?

You can’t have sugar-free wine, unless it has been striped out of the wine. Sugar is a foundation of wine; without it, we would have grape juice. Even dry wines will contain trace amounts. However, you can shop for dry wines with low enough levels that you don’t have to worry about your health. Stick to natural wineries that abide by the golden rule: nothing added, nothing taken away. Prioritize dry and bone-dry wines, and you’ll keep your sugar intake low. As well as seek out wine producers who are transparent about their practices.

The best news about this? Dry and natural wines are delicious and abundant; you won’t miss out.

Want to start drinking natural wine today? Shop our selection of organic, vegan wine made with minimal sulfites, and fermented dry.