Commonly used unit of measurement for the value or scale (potentia Hydrogenii = starch concentration of hydrogen) for the concentration of the active acids in a solution that is measured by the free hydrogen ions. In viticulture, this is a very important criterion for the growth of the vine, the ripeness and the taste and the durability of the wine. Already the salary in ground (from alkaline to angry ) the temperature and the Rainfall during the growth cycle as well as the vine has great importance in terms of concentration in wine. It is thus expressed, inter alia, in connection with winemaking, the acidity (acidity) in the soil and a wine. Although this is related to the acidity in the wine (sum of different acids), but says something completely different.
The acidity in grams per liter or in per mille states which acids are contained in which quantity in a wine (see table below) total extract ). This has nothing to do with the acidity. The acidity in pH values indicates whether in total the wine (or any other solution) is acidic (0 to 6.9 pH), neutral (7.0 pH = eg water) or alkaline (7.1 to 14 pH). The lower the value, the higher the acidity. For example, have a pH of 0 sulfuric acid or hydrochloric acid. The pH for a wine is on average between 2.8 to 3.8 pH. Incidentally, it does not change or hardly changes over time (see below) bottle aging ).
The pH value indicates whether a wine tastes sour, less sour or not sour at all. This is not so much of that titration determined acid content, but on the amount, type and interplay of many different acids in a wine. The acidity must therefore not be equated with the pH (acidity), as some substances in the wine have an alkaline effect and thus weaken the acidity. Therefore, two wines with the same acid content can have two different pH values (ie acidity levels). Thin wines with low total extract have a high acidity only because of a low pH, because too few extractives are present, which could weaken the acidity.
On the other hand, low pH results in a better one colour, prevent spoilage bacteria and allow more free, active sulfur dioxide, At the sulphurize The principle is: the lower the pH, the stronger the germ-inhibiting effect and the less sulfur is needed. A malolactic fermentation is only possible from a value of 3.2 pH upwards. At too high pH values, as they often occur in wines from hot growing areas and certain varieties, there is a high risk that unwanted bacteria take over the malolactic fermentation. You can then make unpleasant wine mistakes like Lactic acid sting and horse sweat cause.