French Andouille sausage is prepared by using the entire digestive tract of a pig and combining additional ingredients like onions, wine, and seasonings. Traditional Andouille has a much grayer complexion and a distinct odor that separates it from the American version that you'll find populating the aisles of your grocery store. While popular abroad, this type of Andouille sausage is less common in America, which is why you won't typically find yourself accidentally picking it up while shopping.  Instead, the American version of Andouille sausage is made with pork butt (the upper shoulder of the animal) and uses ingredients like garlic, onions, and wine. Additionally, American Andouille sausage undergoes two rounds of smoking: the first round smokes the contents of the sausage and the second round smokes the sausage once it has been fully prepared.