Esters in rum: The secret of Jamaican "funk" - Old Dragon Rum

When rum enthusiasts talk about “high-ester rum” or the legendary Jamaican “funk,” it is more than just shop talk. It is the key to one of the most exciting flavor profiles the world of spirits has to offer.

What exactly happens here chemically, and why does it make a rum taste like overripe bananas, pineapple, or even almost “meaty”? We take a look behind the scenes of rum production.

What are esters actually?

Simply put: Esters are organic compounds that are created when acids react with alcohols. In the world of rum, they are the primary factors responsible for fruity and floral aromas.

While distillation in many other spirits aims to produce a spirit as pure as possible, Jamaican distilleries often pursue a different approach: they aim to specifically “cultivate” these aromatic esters.

The art of fermentation: How “funk” is created

The magic of ester formation does not happen in the still, but during fermentation – that is, where sugarcane juice or molasses turns into alcohol. To maximize ester concentration, traditional distilleries rely on:

Long fermentation times: While “normal” rum is often distilled after 24 to 48 hours, fermentation for high-ester rums can take several weeks.
Dunder & Muck-Pits: This is the best-kept secret of the Caribbean. “Dunder” is the stillage (the residue from the still). In combination with “Muck” (a nutrient-rich sediment of bacterial cultures), a highly active environment is created that helps the yeast in its work and massively boosts ester formation.
Bacterial power: It is not just yeast that is at work, but specifically cultivated bacteria that thrive in this “muck” and provide the extremely intense aromas.

From tropical fruit basket to leather

Why does high-ester rum taste so special? Depending on the concentration and composition of the esters, completely different notes emerge:

Fruity esters: They are reminiscent of extremely ripe pineapple, banana, or mango. This is the typical “Hogo” character that many rum fans are looking for.
Chemical notes: At very high concentrations, it becomes almost acetone-like, medicinal, or leathery – this is the extreme “funk,” which is challenging for beginners but a highlight for professionals.

Old Dragon Rum: Balance through craftsmanship

At Old Dragon, we use the versatility of these Caribbean distillates to create a blend that can do both: it offers the aromatic depth and complexity that connoisseurs expect, while remaining smooth and elegant. Our goal is to combine the Caribbean soul of ester-rich rums with the structure and finesse that define our Spiced Rum.