Rum makers face the following refrain:

“The truth is that the future manufacturers of rum need a clear scientific roadmap to grow their future market and future industry” ….. “Let’s boost the science behind our rum industry. Let’s get that right."

Notwithstanding the reputation for global excellence, there has been a longstanding perception that Barbados Rum making is antiquated. It is true that Rum making proudly adheres to longstanding traditional processes and favours sense driven organoleptic testing over dispassionate, clinical analytical testing. Protecting these methods and processes has been a challenge to industries such as rum in the developing world where well-meaning bureaucrats, desperate to promote economic advancement, can have an unfortunate long term negative influence.

The business world of wines and spirits is notable for the strength and prominence of long held family businesses ably competing against brands held by corporate giants. Family controlled entities will often take the ostensibly irrational, passionate decisions that an MBA educated board will never contemplate.

Traditional methods, though costly, are now valued higher than ever before. From Cuban cigars to Champagne, affluent consumers will pay the premium for skilled artisanal products. No matter how skilled the MBA or the accountant, no level of efficiency can overcome the intrinsic high costs of manufacturing in Barbados. However, authentic, traditional methods delivering excellence have proven we can deliver a viable export rum product despite our cost handicap.

Economic forces make change inevitable, no matter how passionate producers want to cling to traditional practices, and rum making has undergone change. The modern Barbados style was developed at the turn of the 20th century with the advent of selected yeast fermentation and continuous distillation. However, Barbados Rum is notable for retaining small copper batch (pot) distilled rum as an indispensable component.

Challenges to Fermentation Methods

Challenging traditional practices in rum is nothing new. Leonard Wray in his seminal work, the ‘Practical Sugar Planter’ published in 1847 related:

“It is not more than a few days ago, that I was asked by a person why yeast was not used by our sugar planters as ferment intimating in very significant terms, that he considered all the West India distillers a very choice pack of fools.

The prescient Wray also stated:

“No foreign agent — such as yeast — is necessary. Nay, further, that such is extremely undesirable; as it would change altogether the character of the fermentation”

The first serious challenge to the traditional approach would come from Jamaican chemist Percival H. Greg. Greg was strongly influenced by the work of Emile Hansen and travelled to Copenhagen to work at the Carlsberg laboratory. Greg became convinced of the merits of isolating, selecting and pitching a strain of yeast as was now becoming practice in breweries and distilleries around the world. Writing in ‘The Sugar Cane’ in 1893, Greg advocated:

“Not only must we do away with spontaneous fermentation by using a ‘pitching’ yeast, as brewers term it, i.e. adding some previously prepared yeast to set our vats in fermentation at once, but I strongly recommend the selection and cultivation of a suitable type of yeast in a state of absolute purity”

The challenging economic environment for colonies in this period (occasioned by the sugar beet ‘bounties’) resulted in serious challenges to the traditional methods. The Jamaica Board of Agriculture in 1903 published:

“On the advice of the Board, the Governor asked the Legislative Council to vote the amount necessary to obtain the services of a specialist in fermentation to cooperate with the Chemist in the study of the conditions of the manufacture of rum; in the investigation of means of increasing the yield and improving the quality; in the study of the types of yeast operating in successful and unsuccessful fermentations and the practical application of such information”

The Carlsberg Lab would revolutionise brewing and methods of adding selected yeast strains would become the standard, and today almost all beers, wines and spirits on the market proceed in this way as outlined by Hansen in the 19th century. Selected yeast strains are used to generate efficiency and consistency.

At Foursquare we practice both modern (i.e. 19th century) fermentation and traditional fermentation methods (dating to the mid 17th century). Under the modern method, fermentation proceeds by the addition of a commercially produced yeast strain to molasses from a central sugar factory. Fermentation efficiency is high and completion over two to three days is an order of magnitude better than traditional methods typically measured in weeks. Results are consistent.

The traditional method proceeds entirely from sugar cane juice milled on site at Foursquare. No exogenous yeast is added. Fermentation proceeds entirely from the naturally occurring yeasts and bacteria within the freshly milled juice. The process takes weeks and requires considerable experience and know-how to manage.

With traditional fermentation, there is little sense of manufacturing control. Nature is in control. The terroir of the cane and the vagaries of the climate (i.e. the vintage) come to the fore. The skill in managing the process, which can only be learned through experience, does allow us to nudge, cajole, persuade, inveigle these natural processes. Keeping these links to nature are what make our rums unique and valued greater than ever.

There is a role for science. We understand our natural processes so much better than our predecessors, thanks to advances in biology, and our methods of ‘persuasion’ are greatly informed both by this better understanding of biology and by the use of modern analytical laboratory methods to monitor our wholly natural process.  

Advent of Continuous Distillation

As discussed in my 2023 article, Barbados Rum making was radically changed at the turn of the century by the advent of continuous (column) distillation.

Despite its superior efficiency, distillers, no doubt responding to the demands of the blenders, never gave up on their pot stills. Modern Barbados Rum is a blend of pot and column distilled rums. Pot still rums are today considered an indispensable component of the Barbados Rum style.

The remarkable preservation of these methods cannot be understated. By the 1950s all three remaining distilleries (from 158 distilleries in 1856) operated a continuous (column) still. The 1954 Advocate Year Book described rum making in the following context:

“For many years, Rum was made in a crude manner in small stills on various sugar plantations.”

The Year Book described the first continuous column still distillery as “specially organised so that every step of the manufacturing process was scientifically controlled” and kept “up to date “by the “constant addition of the most modern equipment”.

Nevertheless, the pot still survived. It was not the bureaucrats, the accountants, nor the boards of directors that saved it. It was the irrational and stubborn decision making of men like Darnley Ward at Mount Gay. A 1980 New York Times article informed readers that:

“The original type of rum is the preferred drink of Darnley D. Ward of Bridgetown. It is one of the few companies in the West Indies still making the old redistilled rum.”

At Foursquare we also operate a continuous column still, but we have two batch copper pot stills. Here again, the preservation of the method is one thing, but it is how we embrace and adapt technology to this process that is more notable. Copper was chosen for still making because it was malleable and an excellent heat conductor, but it also introduced scale to still making. Scale of production made rum (and all distilled spirits) possible for social drinking. The advent of a (relatively) large 500 gallon copper pot still on a sugar plantation meant making enough rum not just for the plantation but enough to send to Bridgetown. Ligon (1647) describes:

“This drink is also a commodity of good value in the Plantation for we send it down to the Bridge, and there put it off to those that retail it. Some they fell to the Ships, and is transported into foreign parts, and drunk by the way.”

But as those who tried to substitute copper with modern materials discovered, it did more than offer scale. During distillation, copper catalyses reactions that remove unpleasant Sulphur compounds from distilled spirits. A still made of copper is essential to making quality spirits.

Following many years of research, in collaboration with us and the University of Siena in Italy, Green Engineering developed and patented the first nano-copper surfaces to be used in distillation. The practical effect of these copper surfaces is to improve the catalytic effect of the copper. In this way, the traditional thermodynamic process is unchanged, but the discovered beneficial effect is improved. Modern material science improves our 17th century rum making method.  

Striking the Balance

At Foursquare, I like to think of us as striking the right balance. We actually loathe words like ‘innovation’ or ‘experimentation’. They are very popular in the marketing departments of many spirit makers, but those words imply change is desirable. We are proud of what we do and the legacy we have inherited. Our job is not to innovate or experiment. Our job is to protect our legacy and to do it well. That is the framework in which we embrace technology and the framework by which the passionate people are the ones empowered.