Brown sugar is a type of sugar that contains a small percentage of molasses, which adds a brown color, some moisture, and a small amount of molasses flavor. Brown sugar was the original kind of sugar, as before modern refining processes made white, fine grained sugar possible, sugar was made from evaporating cane juice, which results in a naturally brown product.

Today, most brown sugar is divided into light and dark types, where the only difference is the amount of molasses added. Other types of brown sugar include Muscovado (which is made from evaporated cane juice, and is very dark), Demerrara and Turbinado (which are made from centrifuging crystallized cane juice). 

Other types of brown sugar include Piloncillo, a cone shaped, rock hard Mexican sugar, date sugar, common in Middle Eastern desserts, and Japanese black sugar. 

Brown sugar adds dimension, complexity and a rounder sweetness than white sugar does to cocktails. 

Some popular cocktails containing Brown sugar