Everyone has come to taste lemon juice, salt or coffee (without sugar), obtaining particular and strong feelings: these feelings, and many similar others, are called "hardnesses" due to their "hard" nature.
Hardnesses are important because, along with the softnesses, they contribute to the final taste of the wine. It is important that they do not prevail over others, and vice versa, because the final taste may be unpleasant.
Hardness sensations can be of two types: "taste" and "tactile". The first are perceived through the taste buds on the tongue: they are acidity, bitterness and sapidity. The "tactile" sensations are perceived with the sense of touch: the main one is astringency.
Hardnesses depend mainly on the type of grapes, the land and the climatic conditions in which they grew. They are more pronounced in white bubbling and sparkling wines, easily perceptible at a temperature between 4 ° C and 12 ° C.
The acidity is a taste sensation due to the presence of acids dissolved in the wine (e.g. tartaric, malic, citric), that causes a fluid salivation.
It is most commond in white wines, especially in the those produced with premature grapes or in areas with a cooler climate.
Bitterness is a tasty sensation due to the presence of several chemical compounds, which is often perceived as unpleasant.
It is the sensation we are most sensitive to and it is commond in almost all types of wine. The same ethanol, but it is not the only one, has this particular flavor.
The sapidity is a taste sensation due to the mineral components dissolved in the wine, that causes a muddy salivation, i.e. more dense than usual.
It is common mainly in white wines, in which is higher the acidity.
The astringency (known also as tannicity) is a taste sensation that is felt like a kind of dryness and roughtness in the front of the mouth and the tongue, similar to the one you try easting a persimmon or drinking a bitter tea.
It is present only in red wines, given that the phenolic and polyphenolic compounds that compone it (also called tannins) are contained in the skin and inside the seeds of the grapes, and are released only with the maceration.
DO you know that...
The perception of hardnesses is strongly influenced by the temperature of the wine, so it is important to taste a wine according to how the producer has thought: for the reds 14-18 ° C, for the white 10-14 ° C. We avoid drinking a red wine stored in the refrigerator or a white wine at room temperature: the first would be sharp, the second dish.