When we talk about different flavours whether it be light floral notes or heavier rich molasses , we are often actually noting the effects of different distillation techniques. Many spirits use a single method, because rum was developed by different colonies it has meant that many various approaches are used even today.
<img src="http://static1.squarespace.com/static/50dc42a0e4b00220dc73b4b8/t/515e0ca0e4b054dae4021beb/1365118163076/the+port+mourant+double+wood.jpg" alt="the port mourant double wood.jpg" />
The classic copper pot stills the much of those lightest floral banana notes come from the primary part of the distillation which can be altered by deciding the extent of the “heads” (the first alcohol from the still) is allowed or cut out. Similarly the end of a distillation, the “tails” produce the oily, richer congeners often referred to as the ‘fusel oils’ in a rum. Defining the cut of heads and tails is not as simple 10 or 20 percent off each end. It is a timed cut to determine the signature style the producer wants to create in their rum.
<img src="http://static1.squarespace.com/static/50dc42a0e4b00220dc73b4b8/t/515e0d55e4b0daad6e7bbb69/1365118294063/Antoine+Pot+with+Retort.jpg" alt="Antoine Pot with Retort.jpg" />
Column distillation as a process tends to produce much lighter textures in rum as a process. They also use collection plates at different points of the column to determine the rum the distiller would like to achieve. They may take upto twenty ‘cuts’ from various heights of the continuous distillation with very different alcohol strength and flavours. An often overlooked defining character in agricultural rum, or ‘rhum agricole’, made in Martinique is the that the local A.O.C. restricts the column still to only have a maximum of 9 concentration plates and a diameter not exceeding 2 meters.
It must be remembered that there are many other process such as the use of a retort or "doubler" that can have additional impacts beyond the simple use of different types of stills. A retort (seen right) act to create a high alcohol content off the first distillation, which may mean the rum won't be distilled a second time and may have more heat in the final distillate (newly made rum/alcohol). It must be remembered that when producing rum that there can be no statement of 'better' styles of rum. Whether it be column or pot distillation good practices of marrying the right distillation technique to a particular type of barrels for the right amount of time. But the final product can only start with a good primary distillate to use in future ageing process.
ABV (Alcohol By Volume) % is instrumental in determining the intensity of the flavours achieved in distillation. This is partly due to the levels of water needed to bring down the distillate to a bottling percentage much like many bartenders use juice to lengthen out of cocktail. If rum comes off the still at 90% ABV and the bottle in front of you has a ABV of 40% then over half of the bottle in front of you is water. Although not many rum producers would distil so high because there would be considerably less flavour, these high percentages best left to vodka. For rum the ABV intensity as defined by the column plates or the length of a pot stills neck can often affect the flavour of the rum and are important parts of the rum you drink.
The cultural differences between various colonies meant that producers were asked to design rum for the palates of the mother country. As rums change and develop today not much has changed, with each advancement or new technique used we see rum moving in many different directions capturing many different palates. In rums now global market there is many more than just a single colony it has to satisfy.