What determines the SWEETNESS of the wine?

What would be your answer to this question?

This question, which may seem banal, in reality allows us to investigate different aspects which contribute to the achievement of this sensation perceived by our palate as we are tasting the wine.

Let’s start by saying that the basic tastes that we can identify are these four: acidic, salty, sweet and bitter and from the combination of these four flavours arise all the other flavours.

We are able to identify these flavours thanks to the sensory receptors present in our oral cavity and which are called taste buds. To be more specific the sweet flavour is identified mainly by the taste buds at the tip of the tongue.

It is interesting that this sensation identified by our tongue is not exclusively traceable to the sugars present in the wine that we are tasting, but also to other factors, internal and external to the wine, such as the alcoholic content or the serving temperature of the wine itself. 

Let’s try to better understand these three components.

Having already read our articles about the fermentation process we learned how the sugars present in the grape must, become metabolized by the yeast and transformed into alcohol.

But in reality, not all the sugars are metabolized completely, due either to the sugar’s natural structure or to the choices made by the winemaker. For example, some types of sugars, such as those defined as "pentose sugars", cannot be transformed into alcohol by yeasts due to their structure. On the other hand, the winemaker may choose to halt the fermentation at a specific moment, determining how much glucose and fructose to leave in the wine. The set of these sugars defines the "sugar residue" and contributes to our perception of sweetness.

On the basis of this indicator, a scale of sweetness has been defined according to the residual sugar present in the wine, which defines still wines as "Dry" (less than 5 g/l), "Semi-dry" (between 5-30 g/l; up to 15 g/l it is defined as “Abboccato”), “Semi-sweet” (between 30-50 g/l), “Sweet” (above 50 g/l).

For sparkling wines this scale of sweetness varies, as the effervescence given by the carbon dioxide present in them, given its acidic action, tends to attenuate the perception of sweetness in the wine, harmonizing wines which often have very high quantities of sugar residues. The sweetness scale for sparkling wines is: "Brut Nature" (less than 3 gr/l), "Extra-Brut" (from 3-6 gr/l), "Brut" (from 6-12 gr/l) , “Extra dry” (from 12-17 g/l), “Dry” (from 17-32 g/l), “Semi-dry” (from 32-50 g/l) and “Sweet” (over 50 g/l L).

As discussed above, another component in the wine that contributes to the sensation of sweetness that we find when we drink a wine, are the alcohols present in it.  In our mouths the alcohols provoke a sense of “sweetness” similar to the sweetness from the sugars and as a result they may accentuate the sensation of sweetness that we perceive.

Let's give practical examples of wines that we will introduce to you in more detail in the next articles:  “Il Sapiente Limited Edition” is a Barbera Sangiovese blend (60% Barbera – 40% Sangiovese), greatly appreciated by our partners because it is an innovative wine in an elegant guise. It has a residual sugar of about 10gr/lt, therefore it is a "sweet" wine, a very "international" taste, whose softness is also perceptible thanks to the high alcohol content (15%), a significant amount but not so strong as to limit the drinking.

But we said that there is another external factor that influences the perception of sweetness in a wine, and we are speaking of temperature.

The serving temperature of a wine can change our perception of the sensation of sweetness, falsifying it. Why are sweet wines usually served at a low temperature?

Because this compensates for the high presence of sugars that otherwise may not be so pleasant.

In the case, for example, of red wines, which are served at a higher temperature, the temperature stimulates the taste buds and tricks our brain into perceiving greater sweetness. This phenomenon is defined by wine makers as ‘Thermic sugars’.

We have tried to explain to you in a simple way what causes the sensation of sweetness during a wine tasting, and as we have discussed above, this sensation confers to the wine a certain ‘softness’. In the next article we’ll talk about this topic.