Ethanol, also named ethyl alcohol according to chemical nomenclature of IUPAC (International Union of Pure and Applied Chemistry), is the second homologous of the series of the so-called saturated fatty alcohols. It is better known in a practice just as alcohol. It has the molecular formula C2H5OH and molecular weight 46.07 g/mol. The methyl alcohol CH3OH is the once with lower molecular weight than ethanol in the same homologous series. It is the most often accompanying fraction in industrial production of ethanol by the so-called alcoholic fermentation. It is obtained as an adjunctive component due to various pectin substances and other methyl esters in the substances used as feedstock for the alcoholic fermentation. The alcohol (ethanol) fermentation is a process of conversion (transformation) of simple sugars such as glucose, fructose and sucrose to ethanol and carbon dioxide according to the following chemical equations: 

The process of alcoholic fermentation in a practice is realized under the action of yeasts. The most frequently used are Saccharomyces Cerevisae species. Of course, some other types of yeast and microorganisms also have the ability to carry out this conversion.

Due to its functional OH group, named hydroxyl function, ethanol has the ability, like other representatives of the same homologous series of saturated alcohols, to form the so-called hydrogen bonds with water, which gives it the ability to mix with water in any proportion. An interesting fact is that the mixing of ethanol with water leads to a reduction in the total volume of the solution, a process known by the name contraction.