Beer is created by the chemical process of Fermentation. Yeast consumes sugar and produces CO2 and Ethanol. Ethanol also commonly called ethyl alcohol, drinking alcohol, or simply alcohol is the principal type of alcohol found in alcoholic beverages. CO2 is allowed to escape the fermentation tank. Later, during the bottling process, the CO2 will be kept in the bottle to carbonate the beer. This process is called bottle conditioning.