Production process

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The process of making distilled spirits can be considered as three distinct phases: fermentation, distillation and maturation.

– Fermentation is the process of converting sugar into alcohol using yeast. The flavour and aroma of the raw spirit is created here.

– Distillation is where alcohol and aroma are separated from the wash and becomes concentrated. The distiller chooses what parts to keep and what parts to discard.

– Maturation involves resting the spirit to help remove some off-flavours. This constitutes “aging” when it occurs in an wood barrels. The wood will impart colour and flavour to a varying degree.

Traditionally, a rum distillery was always closely tied to a sugar plantation. They were often simply regarded as way to make money from sugar refinery waste (molasses is a by-product of sugar extraction). Some enterprises did focus on rum production though. This could shift depending on price of sugar on the export market. Sometimes, more money could be earned processing sugarcane into rum.

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Fermentation

All beverage alcohol is made from sugar. In the right conditions, yeast will metabolize sugar into ethanol and carbon dioxide. When making bread, the produced carbon dioxide is what makes dough rise. The alcohol is retained and accumulated when making alcoholic beverages. The produced alcohol is later further concentrated by distillation when making spirits. Alcoholic beverages are typically named according to the raw product from which they were produced.

While most rum is fermented from sugarcane molasses, some distilleries make rum from fresh sugarcane juice (rhum pur jus, rhum agricole). Note that sugarcane juice is more difficult to work with than molasses. It degrades quickly. The resulting spirits, however, has herbal notes that cannot be obtained with molasses. More on rhum agricole : https://inuakena.com/misc/war-emancipation-beets-tariffs-technology-earthquakes-volcanoes-quotas/.

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Distillation

Distillation is the process of extraction by evaporation. Because ethanol boils at a lower temperature than water, its possible to concentrate and purify it by boiling it out of a mixture and collecting it as vapour. Spirits are produced by distilling alcohol created through fermentation.

The process (discontinuous distillation) : An alcoholic liquid is heated in the kettle until it boils. This produces hot vapour that travels up and through the chamber of the still until it is directed to the condensor. The condensor is essentially a water jacket that cools the vapour back into a liquid as it passes through. The aroma and flavour of the distillate will change during the course of a batch. The distiller usually removes and discards undesirable parts of the production. Most of the water and everything else not volatile gets behind in the kettle.

Yeast strain, wash composition, fermentation temperature and still configuration will all have an influence on the characteristics of the resulting rum. Most rum distilleries produce multiple recipes and use code names, known as “marks”, to keep track of stocks. While sometimes individual recipes/marks are packaged as-is, they are most often blended together to achieve a specific flavour profile. This also improves consistency.

Carroll’s Distillery produces marks that suit a large range of styles.

IFV : “It’s F***ing Vodka”. The most neutral rum. The second distillation is on a reflux still with 8 rectification plates. Distilled above 90% alc./vol. It is mixed with flavourful rums. (Used to be a Gannet component, no longer produced).

CF : “Column Flavour”. The second distillation is on a reflux still with 8 rectification plates. Distilled above 90% alc./vol. but with parameters that allow for more flavour than IFV. Floral and delicate. Later batches of Gannet are wholly comprised of this.

PA : “American Pot”. Double pot still. Second distillation has no rectification plates. Distilled at between 75 to 80% alc./vol. An oily rum with spicy notes.

RHE : “Red High Ester”. Contains a lot of esters and the aroma reminds of red fruits, like strawberry and cherry. The first release was measured at 567 g/hLAA .

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Maturation

Spirits are often rested after distillation. Coarsely distilled rum tends to soften over time. These can mature in inert containers, but most rums and other ‘brown spirits” are stored in oak barrels. Oak barrels were long ago the default container for storing and transporting liquids. The practice continues today because of consumer taste.

The duration of time a spirit is stored in barrels is know as it’s age. The process of aging infuses rum with wood flavour and allows the most volatile, often undesirable, congeners to evaporate. The size and condition of the barrel, the alcohol content of the spirit and the temperature of the environment all have an influence on how aging affects a spirit.

While aging is the process of resting spirits in an oak barrel, maturation is more broadly the development of quality over time. Rum can age forever (as long as it doesn’t completely evaporate), but it’s maturity will peak at some point. The quality will eventually decrease. Too much wood infusion, evaporation and oxidation will eventually overwhelm fermentation flavours and degrade the quality of spirits.

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Adulteration

Rum often contains additives to improve it’s commercial appeal.

Aged rums are almost universally coloured with small amounts of caramel colouring. Darker spirits are more appealing and suggest a stronger infusion of wood. On an industrial scale, it also allows the colour of a product to remain consistent between batches. While this generally does not affect flavour or aroma, “black rums” contain enough of it that it gives a characteristic slight bitter taste.

Some brands of add small amounts of sugar and or glycerin to their product. While not permitted by law, the practice is unregulated. In principle, sweetened spirits are liqueurs. Thankfully, lists of rums that contain sugar have been compiled and are readily available on the internet : https://rumproject.com/rumforum/viewtopic.php?t=1683. The blog DuRhum tested some popular rums for glycerin in 2015 : https://durhum.com/here-we-rum/ (translated from french).

According to the Canadian Food and Drug Regulations, rum sold in Canada can contain “fruit and other botanical substances” and “flavouring and flavouring preparations” (https://inspection.canada.ca/en/about-cfia/acts-and-regulations/list-acts-and-regulations/documents-incorporated-reference/canadian-food-compositional-standards-0#a2.). The extant of undeclared flavouring in rum is not known. Some products do declare flavouring (example : spiced rum). A small number of “botanical rums” exist, where a sugarcane spirit is infused with botanicals in a similar methods to gin.

Furthermore, according to the Canadian Food and Drug Regulations it is “recognized in regulatory guidance and industry standards” that up to 9.09% (out of 100% total amount) of the alcohol in a spirit can come from anything without affecting compositional standards. Rum can be mixed with other spirit types and wines and still be labelled as rum.

Fortunately, countries known for rum making tend to have stricter rules within their borders. A number of “Geographical Indications” are slowly being prepared that will hopefully one day insure rum has the same protection abroad. Rum bottled directly by distilleries are generally less likely to have adulterants.

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Styles

Different technical and philosophical approaches to rum production around the world have resulted in a wide range of flavour profiles. While all spirit classes have sub-categories to a certain degree, rum is so diverse that a person not familiar with a particular style may not even identify it as rum altogether. A number of classifications systems have been developed to tackle this :

– Colour : white – amber – dark – spiced / flavoured. This assumes that the darker the colour, the more there is flavour and wood presence.

– Country / language : english – spanish – french. Countries that were colonized by the same groups tend to produce similar rum. Often used in conjunction with colour.

– The Gargano classification : Pure Single Rum – Traditional Rum – Single Blended Rum – Ordinary Rum. The categories are defined by distillation, in parallel to the Scotch Whisky system.

Although easy to understand, colour classification completely fails to capture the characteristics of a spirit. Colour has little relationship with flavour and aroma. Most dark spirits are coloured with caramel colouring in order to suggest extended barrel aging and even the most flavourful spirits pour out the still perfectly clear. Knowing the country a rum is from does indeed give a lot of information about the profile. Individual distilleries, however, have been producing increasingly diverse rums and so the country of origin itself is not a tell-all. Neutral spirit can be produced anywhere. Classifying rum directly by production method (even if it’s just pot, column or blend) has a lot of benefits. Mainly, it is the only way to properly distinguish artisanal production techniques. The distinction is an essential step to lift rum’s reputation to where it deserves. The catch is that few rum labels carry production information.

For everyday use, I find it’s best to describe rum as being light, medium or heavy-bodied and unaged, x years aged or black / flavoured (e.i. additives). This is generally understood by the public without requiring any background.

Carroll’s Distillery produces styles that are light (Gannet, Sandpiper, Gadwall), medium (Cormorant) and heavy-bodied (RHE high ester content).

Further reading :
https://www.velier.it/en/rum/3690-the-gargano-classification-how-to-distinguish-great-rum.html
https://cocktailwonk.com/2016/10/categorically-flawed-rums-classifications-hold-back.html

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Consumption

Rum can either be drank as-is or mixed with other drinks. While well matured / carefully produced bottling can only be fully appreciated neat, the vast majority of rum is drank mixed. Flavoured rums are exclusively designed for mixing.

Neat rum is best appreciated in special nosing glasses that concentrate aroma. Aromatic experience is just as highly prized as taste. A variety of glassware exist for this means and the preference is personal. The importance is that the glass narrows towards the opening.

Rum is most often drank mixed with soft drinks. If there are three ingredients or more, it’s known as a cocktail. Each ingredient has a role and the new beverage becomes more then the sum of its parts. Base spirits like rum provide alcohol content but may contribute in a small or large way to flavour depending on how assertive it’s character is.

Cocktail recipes are found in “Cocktail Corner”.

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