Depending on the type of red wine you drink, a single glass can contain anything from less around 1g of sugar (less than a quarter of a teaspoon) right up to 15g (nearly 4 teaspoons!) per glass. Below I'll go through how sugar makes it's way into red wine, along with the best and worst offenders if you are trying to cut down your sugar intake.
Sitting down and relaxing with a glass of red wine after a long day of work is a perfect way to unwind. It takes your mind off the stresses of the day, offers antioxidants, and is a healthy beverage if enjoyed in moderation. Red wine does, however, contain some sugar, and if you are trying to live a sugar free lifestyle, it's important to understand how much sugar is in your red wine, what type of sugar it is, and where it comes from.
Where Does The Sugar In Red Wine Come From?
Sugar in red wine comes directly from the grapes used in the fermentation process. Grapes contain lots of sugar, typically at least 15 grams per cup, depending on the exact type of fruit and how long it has been maturing. This sugar is critical to the wine-making process. In fact, without sugar, wine couldn't be made!
The alcohol content in wine comes from the fermentation of this sugar by yeast. Yeast is a microscopic organism that consumes the sugar for energy in order to replicate and reproduce. The byproduct of this consumption of sugar is alcohol. Once the yeast are no longer able to digest the sugar, any left over sugar will be part of the final product you have in your glass. In short, the sugar in your wine comes from undigested sugar that exists in grapes.
What Type of Sugar Is In Red Wine?
The type of sugar in a glass of red wine is a complex question to answer, simply because grapes contain several different types of sugar to begin with. Grapes use photosynthesis to produce sucrose molecules. Sucrose is then broken down into two more types of sugar; fructose and glucose. Typically, by the time the grapes are harvested, their sugar content will be comprised of around 20% simple sugars such as fructose and glucose. Beyond these sugars, grapes also consist of xylose, rhamnose, and arabinose. These types of sugars are much more complex and cannot be digested by the yeast, therefore they will always be present in wine.
Many winemakers also add sucrose during the process, in order to increase the alcohol content of the wine. This boost of sugar allows the yeast to produce more alcohol. The process of adding sugar does not typically increase the sugar content of the final product, as most of the added sugar is consumed by the yeast.
In the final product, glucose and fructose are the primary residual sugars and these typically give a red wine it's sweet taste.
So How Much Sugar Is In Different Types Red Wine?
No matter how much fermentation occurs, sugar will always be present in red wine. Some sugars simply cannot be digested, and complete fermentation of both glucose and fructose is, in practice, difficult to accomplish and usually not beneficial to the taste of wine. However, between styles of red wine, there is a distinct difference in sugar content.
Pinot Noir - A popular wine for many people, pinot noir is "lighter" than other red wines. It is a dry wine, and contains very low sugar levels. In fact, residual sugar levels are usually well below 0.5%. This means that each glass of wine holds only about 1 gram of sugar.
Merlot - Merlot is another popular red wine choice, and also contains a low concentration of residual sugars. Merlot offers many earthy flavors that shine through, along with a strong tannin presence. The low sugar content of this dry wine, around 1 gram per glass, makes this a great choice if looking for a wine with few residual sugars.
Malbec - A medium to full-bodied wine, Malbec's usually have a high alcohol content, as well as plenty of tannins and acidities. It is however, low in sugar, due to the high alcohol content and near complete fermentation of sugars by yeast. Malbec's are very close to being completely fermented, offering a dry flavor and fewer than 1.5 grams of sugar per glass.
Zinfadel - Wines of this type exude flavors of blueberry, cherry, cranberry, and other sweet fruits. Usually lighter in color than other types of red wine, they are actually fairly high in sugar content. Typically classified as a medium sweetness wine, they can contain almost 20 grams of sugar per glass. This may vary depending on the blend, so be sure to do your research when purchasing this complex wine.
Sweet Red Wine V Dry red Wine
When purchasing wine, another good way to determine sugar content is to look to see if it is considered sweet or dry. While style, such as Malbec or Merlot, is a good indicator as to how much sugar should be in a wine, looking for a sweetness designation is another foolproof method. Also, there may be variation within a style of wine based on the winemaker's discretion, but sweetness is related directly to sugar content.
Wines with a "Bone Dry" designation have undergone a significant amount of fermentation, leaving behind few residual sugars. These types of wine usually contain less than 1 gram of sugar per glass.
In a single glass of "Dry" wine, you are consuming no more than about 2 grams per glass. This varies between styles and wineries, so be sure to look into specifics for each bottle you purchase.
Wines in this group are starting to settle for incomplete fermentation, resulting in around 6 grams of sugar per glass.
This is when wines start to become loaded with sugar. Expect a sweet wine to have about 13 grams of sugar per glass.
Drinking a single glass of very sweet wine can have well over 15 grams of sugar. These wines have barely undergone any fermentation, and usually contain a lower amount of alcohol than other wines. These wines can be tempting due to their lower alcohol content and more palatable flavor, however they contain more sugar than any other class of wine. While this is still better than a can of Coke, which contains 39 grams of sugar, these wines are not ideal when attempting to cut sugar out of your diet.
The World Heath Organisation (WHO) recommended daily sugar intake for an adult is 25g (7tsp) for a woman and 35g (9tsp) for a man, so as long as you stick to the dryer reds then you should be fine.
What about the sugar in white wine?
I have written another post here outlining the sugar content of white wines.
The bottom line
When it comes to drinking red wine, sugar usually isn't a major nutritional factor. Do be aware, however, that all wines contain some residual sugars from incomplete fermentation. Also, pay attention not only to the style of wine you are drinking, but also the sweetness. Stick to dry wines for the lowest sugar content possible if you are trying to keep your sugar intake down.