is a clear, corrosive, flammable liquid with sour taste and scent. It is manufactured by fermentation of ethanol or carbonylation of methanol or oxidation of acethaldehyde. Mixed with water it is termed as vinegar for household applications. The acetic acid is in Europe and Asia for many centuries now used as seasoning. The discovery of it is estimated at 5000 BC. In nature the acetic acid can be found in saps or essential oils.