What Do We Mean By High Ester Rums?

Pick up any bottle of rum and it contains esters. Jamaican rums in particular are renowned for their super-flavourful characteristics and incredibly high number of esters. These ester rich rums (also known as funk-bombs) are increasingly in demand as more and more people catch the funky-rum bug.

But what are esters and what qualities do they impart in rum?

Esters are completely natural compounds that are created through chemical reactions initiated during the fermentation process when yeast mixes with molasses. Esters give a diverse range of aromas and flavours to rum. Some esters provide characteristics of fruitiness, butterscotch or caramel, whereas others will have more medicinal and solvent qualities. Many rums owe some of their very special character to esters. The most abundant esters found in rum are Ethyl Acetate and Ethyl Butrate. Ethyl Acetate has aromas of green apple, pear and nail polish remover, whereas Ethyl Butrate displays a dominant aroma of exotic fruit, in particular juicy pineapple.

Savanna Distillery's Fermentation Tanks [Flicker]

High ester rums are distilled using pot stills, as the less rectification equals more flavoursome esters. The number of esters will vary depending on the length and purity of fermentation. Jamaican rums are typically high in ester count as distillers expressly coax a higher range of esters through an extended and less controlled fermentation than their Caribbean neighbours. Typical fermentation in the Caribbean can last for as short as 24 hours, however, at Hampden Estate for example (a distillery lauded for their complex, funky high-ester Jamaican rums) fermentation lasts at least 2-3 weeks.

In addition to this lengthy fermentation, is the use of ‘dunder’ and muck at some distilleries. This is how the magic happens. Essentially, dunder is the left-over stillage once distillation is complete, known in the whisky industry as draff. Most distillers discard their stillage, however, in Jamaica some add this to the fermenters - think of sour mashing in bourbon. Stillage is rich in nutrients and acids which propels the production of esters. To create a truly funky Jamaican rum, we have to talk about muck. Referring back to Hampden Estate (it really is ground zero for Jamaican funk), they also add muck to their fermentation. Muck is an ominous liquid: a mixture of dunder waste, sugarcane and other mysterious substances that is left to brew in outdoor pits creating a breeding ground for bacteria and carboxylic acids to charge esterification. 

The end result of this long and involved process is some of the most distinctive and divisive rum on the market and with an ever growing appreciation and understanding of the flavour profiles of ester rich rums it is certain that the 'funk' is here to stay.

Examples of funky, high-ester rums include:

• Hampden rums, particularly the DOK which comes in at over 1500, however, its worth noting that this is primarily used as a flavouring rather than for drinking. 
• Long Pond rums, including their TECA and TECC mark releases. These marks refer to the ester count within the rum, with TECA containing 1200-1300 gr/hlpa and TECC containing 1500-1700 gr/hlpa. 
• Grande Arome rums, high-ester styles from French island rhums, in particular those of Savanna Distillery on Réunion ​​island.
• Caroni rums - the distillery closed in 2002 but thanks to Velier's Luca Gargano buying up stocks this Trinidadian rum is still renowned today for its distinctive heavy style high ester profile.

Interested in learning more about Hampden Distillery and their unique production process? Read our interview with Christelle Harris, Director at Hampden Estate.