http://broom02.revolvy.com/main/index.php?s=Acid (wine)&item...
Most of the acids involved with wine are fixed acids with the notable exception of acetic acid, mostly found in vinegar, which is volatile and can contribute to the wine fault known as volatile acidity. Sometimes, additional acids, such as ascorbic, sorbic and sulfurous acids, are used in winemaking. [2]


https://en.wikipedia.org/wiki/Wine_fault
Geranium taint
Geranium taint, as the name suggests, is a flavour and aroma taint in wine reminiscent of geranium leaves. The compound responsible is 2-ethoxyhexa-3,5-diene, which has a low sensory threshold concentration of 1 ng/L.[12] In wine it is formed during the metabolism of potassium sorbate by lactic acid bacteria. Potassium sorbate is sometimes added to wine as a preservative against yeast, however its use is generally kept to a minimum due to the possibility of the taint developing. The production of the taint begins with the conversion of sorbic acid to the alcohol sorbinol. The alcohol is then isomerised in the presence of acid to 3,5-hexadiene-2-ol, which is then esterified with ethanol to form 2-ethoxy-3,5-hexadiene.[12] As ethanol is necessary for the conversion, the geranium taint is not usually found in must.


https://en.wikipedia.org/wiki/Acids_in_wine
Sorbic acid is a winemaking additive used often in sweet wines as a preservative against fungi, bacteria and yeast growth. Unlike sulfur dioxide, it does not hinder the growth of the lactic acid bacteria. In the European Union, the amount of sorbic acid that can be added is limited — no more than 200 mg/l. Most humans have a detection threshold of 135 mg/l, with some having a sensitivity to detect its presence at 50 mg/l. Sorbic acid can produce off flavors and aromas which can be described as “rancid”. When lactic acid bacteria metabolize sorbates in the wine, it creates a wine fault that is most recognizable by an aroma of crushed Pelargonium geranium leaves.[9]

http://broom02.revolvy.com/main/index.php?s=Glossary of wine...
A glossary here

Common Wine Faults Charthttp://wine.appstate.edu/sites/wine.appstate.edu/files/Chart...
Distinctive geranium odor, floral, sweet, pungent. 30 parts per ... 4-Ethyl phenol (4-EP). 4-Ethyl guaiacol (4-EG). Trichloranisole (TCA or cork taint). Geraniol.


The Language
https://www.wineandflavors.com/uploads/presse/article_57.pdf
Aug 2, 2012 - known as geranium taint. Geraniol is also a metabolic by product of the preservative potassium sorbate which is the primary cause of this defect ...
[PDF]Geranium taint - Hochschule Geisenheim University
www.hs-geisenheim.de/fileadmin/user_upload/Mikrobiologie/ge...
Geranium taint. Characteristics. Wine smells like geranium. Causes. K-Sorbat is reduced to Sorbinol by lactic acid bacteria after a non-appropriate wine filtration.