Microorganisms are used for the large scale production of alcohol, wine and acetic acid (vinegar). Yeast is used for commercial production of alcohol and wine. For this purpose yeast is grown on natural sugars present in grains like barley, wheat, rice, crushed fruit juices, etc.
This is the smell of alcohol as sugar has been converted into alcohol by yeast.
This process of conversion of sugar into alcohol is known as fermentation.