Various alcohol compounds formed during alcoholic fermentation by oxidation of the primary alcohols. The artificial word consists of parts of the Latin word "alcohol(us) dehydrogenatus", which means "dehydrated alcohol" or "alcohol from which hydrogen has been removed". In terms of quantity, formaldehyde(methanal) is the most important aldehyde. It is used as a disinfectant (formalin solution) and for the production of organic preparations. The most important aldehyde in wine production is acetaldehyde. Aldehydes also play a role in polymerisation reactions (caking of smallest particles). They can also contribute positively to the aroma in low concentrations, for example the phenol aldehyde vanillin. Certain aldehydes are the sensory cause of firn taste (age firn) and air taste (aldehyde clay). See a list of all wine ingredients under total extract.