What does the term 'heavy mark' mean in rum production?

The term 'heavy mark' in rum production refers to a style of distillation that results in rum being distilled to a relatively low strength. This means that the distillate retains more of the heavier congeners, which are compounds that contribute to the rum's flavor, aroma, and body. As a result, rums produced from a heavy mark are often richer and more flavorful, distinguishing them from lighter styles that are distilled to higher strengths and contain fewer of these heavier compounds.

In the context of rum production, heavy marks are typically derived from pot still distillation, which naturally allows for more flavor retention compared to column still distillation. This characteristic is significant for flavor profiles and overall mouthfeel of the rum, making it a crucial part of the production process for certain styles of rum.