As part of our rum consulting practice, we are frequently asked by our clients about the different types of rum available in the world. Most of them are only aware of differences based on color and are very surprised to learn about all the variables that can affect how a rum tastes. Following is a brief summary of the different types of rum, along with explanations that we hope will help you understand the complexity and diversity in the rum industry. These categories are not mutually exclusive (i.e., you can have a Pot Stilled, Naval Style, Aged rum).
The previous blog focused on classifications of rum based on fermentation method, it is now time to talk about how rum is classified based on the distillation method employed.
Rum types based on distillation method:
Pot Still: These are the earliest distillation devices (also used in the production of Brandy and Scotch). A basic pot still consists of three parts: the kettle, where the liquid mixture is boiled, the condenser, which cools down the vapors coming from the kettle, and the gooseneck, which connects the kettle to the condenser. The liquid obtained from this type of distillation is also known as “single distillate,” since it is processed through the still only once. Typically this liquid is processed a second time, thus producing a “double distillate” which is cleaner and stronger than the single distillate. Several distilleries have taken this a step further by running the distillate a third, even a fourth time through the still, obtaining a cleaner, stronger, more rectified spirit at the end of each run. Because the amount of liquid that can be distilled at one time with a pot still is limited to the size of the kettle, distillers employing this method must perform their work batch by batch, which is a very labor intensive process (the kettle must be cleaned in between batches).
Column Still: The continuous distillation system was created in an attempt to make the distillation process more consistent. It also reduced the amount of work required to process each batch, thus allowing for higher volumes of alcohol to be produced. A distillation column is constructed much like a vertical maze, made up of a number of horizontal trays placed at different levels throughout the column. Here the fermented liquid mixture is introduced into the column at its highest level while steam is introduced at its lowest level. As the liquid makes its way down the column, it is heated by the surrounding steam, and the alcohol in the mix is vaporized. Once it reaches the bottom of the column, the “wash” contains no alcohol and is removed through a release valve. The saturated steam is collected from the top of the column and is then cooled down, allowing it to condense. Depending on the type of alcohol desired, column still operators will employ several columns, each one feeding the next, each one producing a cleaner, stronger, more "rectified" spirit.
Luis Ayala is an author and rum consultant with Rum Runner Press, Inc. To learn more about rum, please visit http://www.rumshop.net/ or http://www.rumuniversity.com/.