The fermentation process itself varies immensely from distillery to distillery...
At one extreme is "natural fermentation," where yeasts inherent in the environment are relied upon to ferment the sugars in open vats.
At the other extreme, fermentation is tightly controlled under laboratory-like conditions.
For efficiency and predictability, most commercial rum fermentation processes fall between these two extremes; distilleries purchase and add the specific yeast cultures they want and take basic precautions appropriate to their environment.
Time is also factor for fermentation; some ferments last only several hours while others can take up to two weeks.
We use specifically different yeasts cultures that we employ when we make our Rum to the yeast strain that we use for our Whiskey.
The Fermentation process is all important in achieving a highest quality usable "Wash", to then go into the Distillation Unit that is being used.
Here at Golden Lion, we use a variety of yeast sources to best capture the essence of the Sugar or Grain we are using in the fermentation process.
We often will ferment our Grain Spirits using a Sour Mash fermentation process, a part of the previous mash is reused to start a new Mash wash, but will also use Fresh Mash fermentation process as well for our Grain Spirits.
For our Rums, we use a Yeast culture specifically suited to extracting the most flavour and character from the fermentation process.
During the fermentation process, whether it be Rum or Whiskey, we allow the process to take as long as it needs to complete and we do not rush this at all.