The movement of the wine between arches and tears

How many times have we paused to stare at the wall of a freshly spilled glass of wine. We are enchanted by the slow flow and we try in various ways to interpret those strange drops that descend copiously, forming perfect arches. It is at this point that we begin to make assumptions, to give explanations; and we always find the coolest of the evening who explains everything to us... and maybe he even knows it. But why do arches form on the wall of the glass? Why are the tears more or less slow? Why are the arches in spirits so tight and in wines instead wider? What determines these phenomena?

In wine there are two fundamental components that derive from fermentation processes and are called alcohol and glycerol. They are two compounds that are chemically defined as organic because they derive directly from nature and are not synthetic. Ethyl alcohol is formed from the transformation of sugars by yeasts; glycerol is a product derived from fermentation and is linked to the concentration of glucose. If this is in high quantity, more is released into the wine. In fact, the glycerine concentration in sweet wines is high and the same thing applies to wines deriving from grapes dried.

Well, on the glass we can get an idea of the composition of the wine.
In fact, the arcs and their width are determined by the alcohol that evaporates and then lifts the veil of the falling liquid. Glycerin, on the other hand, is the main component of tears, which will be more viscous and slower, the greater the concentration of this compound.

Imperceptible arches: alcohol concentration 11 — 12.5% Vol.
High and wide arches: alcohol concentration 13 — 16% Vol. (low glycerol concentration).
Tall and narrow arches: alcohol concentration 13-17% Vol. (high glycerol concentration)

So remember that:
- if the arches are tall but wide, the wines will be alcoholic without a large body;
- if the arches are tall but tight, the wines will be alcoholic with a nice structure and texture on the palate (an Amarone, a Barolo, a Brunello behave like this!).

Fabio De Vecchi