Despite no added sugar, why does wine taste sweet

Believe it or not, but sweetness is a perception! Have you ever realised why does the wine taste sweet or have you ever guessed where this sweetness in wine comes from? Some of the common guesses would be of the sugar that’s present in the grapes used for making wines. Surprisingly that's not the case! If you also want to know the real reason behind this, we have some information to share. (Images: Canva)

The wine that is perceived to be sweeter in taste, in reality, has zero residual sugar (RS) left after fermentation. Technically speaking, the more acidity a wine has the less amount sugar would be in it, leading to residual sugar. During the winemaking process, the yeast used for fermenting wine typically converts all the sugar into alcohol which leads to a dry wine. However, during the fermentation process, sometimes all the sugar is not fermented leading to some leftover sweetness in the wine.

Measured in grams per litre, it is the natural grape sugar leftover in a wine that is obtained after the alcohol fermentation process. It can vary from wine to wine and goes unnoticeable while buying. Typically, the wines that have no sugar in them are technically called ‘dry wine’, however, the next time you get your favourite pinot noir, look for details at the back of the bottle and you will see that there is about 8-10 gms of RS/litre in it. But, if you look at the sweeter wines, the RS can go from 35-120 gms per litre.

The sweetness in wine is neither good nor bad and is a characteristic mostly determined by the winemaker. Some winemakers actually add some form of sugar while fermenting it, which can result in sweeter wines, so there is absolutely nothing wrong with it. This method of adding sugar while fermenting is called ‘Chaptalization’ and is used to increase the total alcohol level of the wine when using underripe grapes. This method is commonly opted in France and Germany. However, if your wine smells sweet or fruity at low levels, it actually denotes a fault called “Volatile Acidity”, which happens when the wine is oxidized along with microbial spoilage such as ‘Acetobacter’.