Term for hydrogen-containing, liquid or solid chemical compounds. The hydrogen ions do that sourtaste a solution. One distinguishes between inorganic and Organic acids, In the wine there are mostly organic acids of the group carboxylic acids available in free, in bound and to a small extent also in volatile form. The term "acidity" should not be understood negatively, because a wine tastes good without this important ingredient flat and dull. It is only through this that he gets refreshing strength, and it is only through that that he comes Sweet better to show off. Wines from hot areas often have a lower content. Not mature grapes own different each vine a high proportion.
Certain acids such as malic and tartaric acid are already contained in the grapes, while others such as acetic acid and lactic acid are only found in the grapes fermentation educated. For reasons of preservation, must or wine are also added to acids. For example ascorbic acid and sulfur dioxide, which is in contact with the water in the wine sulphurous acid forms. The acidity in wine denotes the amount or concentration of acids. This is through titration determined and expressed in g / l.
On the other hand, acidity expresses something completely different. The sour The taste of a liquid depends not only on the amount of acid, but also on its degree of dissociation. The degree of dissociation of an acid or base depends on its acid constant (or base constant), its concentration or the one present PH value a solution. The most acidic is tartaric acid, which is almost three times as acidic as lactic acid and one and a half times as acidic as malic acid. Succinic acid and acetic acid are even less acidic.
The acids are in non-volatile acids and volatile acids differentiated, whereby the border is not to be drawn absolutely exactly (strictly speaking there are also medium volatile acids). The amount of all acids gives that total acidity, The three most common non-volatile acids in wine are tartaric acid (0.5 to 4 g / l), malic acid (0.5 to 6 g / l) and citric acid (0.1 to 0.3 g / l), which make up about two thirds of the amount of all acids. The lactic acid (0.8 to 3.3 g / l) is mainly created at the malolactic fermentation by converting malic acid.
There are still smaller quantities Succinic acid. galacturonic. gluconic. glucuronic. glycolic acid. oxalic acid. mucic and cinnamic acid, The non-volatile acids are presented in total as tartaric acid (although there are several) in g / l. The most common volatile acid is that acetic acid (0.15 to 0.5 g / l for healthy wine). As the name suggests, these do not remain in the wine, but slowly evaporate. They are referred to in total as acetic acid (although also several) and are given in g / l.
The amount of total acidity is at White wines about 4 to 9 g / l and at red wines about 4 to 6 g / l. Defense against higher amounts microorganisms positive to durability at. In principle, EU law provides for acid correction for musts and wines, but this depends on the growing zone is. In zone A ( Germany except Baden) and B (growing area to bathe. Austria ) is a partial one deacidification permissible, however one leavening principally prohibited. The sulfurous acid is divided into free and bound. The two make up the whole sulphurous acid whose share in wine is strictly limited. The acids are in the aging respectively. bottle aging not dismantled. For the other wine ingredients see under total extract,
All tools, work and measures in the vineyard during the growth cycle can be found at Weingarten Care, Complete lists of the numerous cellar techniques, as well as a list of wine, sparkling wine and distillate types regulated by wine law are under the keyword winemaking contain. There is extensive wine law information under the keyword wine law,