This also generally as Alterston or typically referred to as "Altl" taste and odor occurs especially in older white wines. The name is derived from the old high German "firni" for "previous year" or "old". This most common type of Alterstons but may not join UTA (atypical age tone), sulfurous off (Lagerböckser) or the related petrol tone be confused. The cause of old age pear is primarily oxidation through atmospheric oxygen, This is due to excessive oxygen intake after the filtration, as well as by high temperatures during storage, intensified by high content of flavonoids phenols in wine. This is also promoted by faulty corks (closures). When stored in wooden barrels, varnishes can be formed after just one and a half years; in bottle storage, this usually takes much longer.
The varnishes are created by Karamellisierungs reactions between amino acids (Protein) and Sugar, The typical bitter taste is expressed by the smell and taste of black tea, old straw, honey, resin, nuts, mushrooms and damp earth. The substances responsible for this are higher aldehydes (Alcohol compounds). The tone can increase to an uncomfortably camphor-like (after the tree) impression. The oxidation leads to color changes up to Hochfärbigkeit, Lovers of older white wines tolerate old age to a small extent and even positively describe it as "noble-minded". In any case, it is a stronger one wine faults, He has other causes Schwefelsäurefirn,