Rum (also known as Rhum in French and Ron in Spanish) is a distilled alcoholic spirit made from the by-products of sugar production, i.e. molasses, or from sugar cane juice and is made by fermentation followed by distillation. Rum can be distilled in continuous or pot stills and is usually aged in oak barrels.
Classification of Rums
There are may different types of Rum and these vary from region to region and country to country depending on the different primary material to be distilled, different production methods and different ageing regimes. Most people only differentiate between rums by virtue of their colour but there are many ways of classifying different rums. Due to the variablity in all the styles and production methods Rum is very difficult to classify but these are some basic classifications.
Edit: Recently there has been a slightly controversial newly proposed rum classification put forward initially by Luciano Gargano (of Italian rum bottlers Velier) who has now been joined by Richard Seale (Foursquare Distillery, Doorly’s) in promoting this. The new rum classification essentially seeks to do away with the traditional classifications of white, golden, dark, French (Agricole) and Spanish style rums. This would be replaced with a system of distinguishing types of rum based on their production, either in pot still, column still or pot / column blends. The idea is communicate the quality levels of rum based on methods of production / blending rather by colour, which may be artificially added, and owes a small debt to Scotch Whisky Classification. Read more here.
Raw Materials for Rum Production
Essentially Rum is either made from sugar cane juice or molasses. As mentioned above some are made from sugar cane juice that is fermented, distilled and then aged. Being made form sugar cane juice means that they retain more of of the original flavours of the sugar cane than rums made from molasses. This is known as Agricultural Rum or Rhum Agricole and are common in French speaking parts of the Carribean and South America. However, the majority of Rum is made from Molasses, which is basically a thick brown liquid left over from the production of sugar. The best are made with the highest grade (Grade A) molasses which contain more fermentable sugar and less of the chemicals used to extract sugar crystals than lower grade molasses. Rum-type spirit has been produced from sugar beet juice but this is not legally a Rum.
Fermentation Methods in Rum Production
There are three fermentation methods used – natural, batch controlled fermentation and continuous controlled fermentation. Natural fermentation is the most simple form of fermentation and relies upon natural occurring yeasts to ferment the rum mash (basically warm water and molasses or sugar cane juice). Obviously not knowing what yeast or yeasts are being used can make this a bit of a hit or miss process and results are sometimes difficult to replicate. The other two methods basically introduce more control, less variability and the ability to produce a more “standardised” product. Controlled batch fermentation is basically the same as natural fermentation but is done using a particular strain of yeast. The strain of yeast used is one of the distillery’s closest guarded secrets as the role of the yeast and flavours it produces can vary from strain to strain. It is almost the fingerprint of a distillery. In this case a batch of mash is fermented usually over two to three days and results are easy to replicate. Continuous controlled fermentation consists of using a particular strain of yeast to ferment the mash in fermentation tanks that are continually receiving a supply of molasses at one end of the system whilst already fermented mash is drawn off from another part of the system and sent for distillation. This continuous method is a relatively new procedure in the Rum industry.
Distillation Methods for Rum
There are two types of distillation used for Rum – distillation using Pot Still (an Alembic or Charentais type still) or a more modern Column Still. Distilling using a Pot Still is a batch process, the liquid obtained is a single distillate. Normally this single distillate is distilled another time to produce a purer, stronger spirit. Sometimes it may be distilled three or four times. The batch size is limited by the size of the still. The Column Still is a continuous distillation system which allows allows for less labour intensive, large batches of spirit to be produced.
Ageing of Rum
Rum can either be aged or un-aged. Un-aged Rum is not strictly a rum but an aguardiente. Any reference to bottle-aged or ageing in stainless steel means it is technically un-aged – Rum only becomes Rum once it has been aged in wooden barrels (these are often old Bourbon Whisky barrels). If a label or bottle has an age statement on it, in the USA it must be the age of the youngest rum in the blend (if it is blended). However, in Europe one is allowed to put the age of the oldest Rum on the label – thus two bottles of identical Rum could be labelled differently in different parts of the world. During the ageing process losses of Rum due to evaporation can be quite high (after all Rum is made in some of the warmer parts of the world) and some countries allow the barrels to be topped up with Rum as it evaporates and some countries do not. Due to the heat of the tropics the ageing process is much quicker than in Scotland for Whisky, for example.
Many producers use prorietary terms to denoted the ages of their product (such as reserve, special reserve etc.) and some will use age statements such as 3, 5, and 7 year old like Havana Club. Other producers have appropriated the term XO from the brandy world for some of their older spirits like Doorly’s XO from Barbados or Ron Milonario XO from Peru.
Blending of Rum
Most Rums produced are a blend of some sort made by mixing rums of different ages and types together, perhaps with flavouring and colouring agents. Usually they will be blended, after maturation, in large quantities, this helps to produce a consistent product. Sometimes Pot Still and Column Still Rums are blended, sometimes those of different ages and styles will be blended.
Two exceptions to this are Single Barrel i.e. a small batch of Rum from a single barrel may be bottled separately and clearly identified as such. There tends to be quite a bit of variation from barrel to barrel and different barrels filled form the same distillation can be markedly different.
The other exception is borrowed from Sherry production and is the Solera method. As with Sherry a Solera is created – this is a series of rows of barrels stacked four or five barrels high. Rum for bottling, the oldest Rum in the Solera, is drawn from the bottom layer of barrels. The space left by removing this Rum is replaced with more from the layer of barrels above and so on until new, un-aged Rum goes into the top (youngest) row of the Solera. This fractional ageing system is also used for Brandy de Jerez. This process ages and blends the Rums as it moves through the Solera with younger and older spirits each contribute something to the final bottled Rum. An age statement will be the average age of the blend. Examples of Solera rums include Ron Zacapa 23 or Botran 18.
Styles of Rum
Another way of classifying Rum is by style. As mentioned before different countries and different regions have ways of doing things. This can roughly be broken down into the following style categories.
French Rum – these are the Rhum Agricoles of the French speaking Carribean and South America. These are distilled in Pot Still and made from sugar cane juice. They tend to be quite fruity with floral notes and produce a spirit in which you can taste the starting product, the cane sugar juice. Rum Agricole has a carefully defined ladder of quality running from Blanc, Ambre, Vieux (aged at least 3 years), Hors d’Age and up to age statements and vintages. A good example of these are those produced by Bally in Martinique, Rhum Barbancourt in Haiti and Rums made in Gaudeloupe.
American Rum – Characterised by distillation in Pot Stills, high levels of congeners and only aged for a brief time in oak barrels. Producers of this sort of style include the Newport Distilling Company (Rhode Island), Railean Distillers (Texas) and Triple Eight Distillery (Nantucket). One of the new American Rum producers is Bayou Rum made in Louisiana, who make an excellent Spiced Rum, as well as their Bayou Select.
Cuban (and Puerto Rican) Rum – Epitomised by one of the most famous Rum brands in the world, Havana Club, these tend to be distilled to produce the lightest, cleanest, most rectified spirit which then derives it characteristics from careful oak ageing and blending. Others include Varadero from Cuba and Don Q and Ron del Barrilito from Puerto Rico.
Naval Rum – Rum has been a traditional Naval drink since the days of the Rum Ration in the British Royal Navy. The Rum was not usually from a single distillery but the Admiralty had a recipe for a blend of Rums from places like Barbados, Jamaica and Guyana. The most famous styles of Navy Rum are Pusser’s, Wood’s and Lamb’s. They are usually quite dark and potent.
Jamaican and Guyanese Rum – The Jamaican style is pungent and usually high in esters. In Jamaica the Rum is sometimes “dundered”. Dunder is the equivalent of Sour Mash or Backset in Bourbon Whisky production. This is essentially the residue leftover from a previous distillation stored in a pit in the heat of the Carribean sun. The dunder becomes quite acidic, which slows down the fermentation process and adds a dramatic pungency (high ester content) to the resultant spirit. Guyanese Rums tend to be medium and heavily-bodied rums, darker in style but quite soft. Good examples of these rums are Appleton Estate and Myer’s and El Dorado from Guyana.
Spanish Rum – Rums from the Spanish speaking parts of the Carribean and South America are heavily influenced by the brandy distilling knowledge and equipment that Spanish colonists brought with them. The Rums tends to have a fruity, brandy-like nose. Normally made in Pot Stills. Good examples of thus style are Ron Zacapa from Guetemala and Flor de Cana from Nicaragua.
Other Rums – other forms of sugar are sometimes used in other countries. In Mexico some distilleries ferment and distill piloncillo which is a very unrefined and moist type of brown sugar. Similarly, in the Pacific Northwest at Bardenay Distillery in Boise, Idaho use brown cane sugar.
Most Rum producing countries produce flavoured Rums of some sort. These are fruit flavoured and spiced Rums usually made from un-aged Rum (so technically not Rum). Famous spiced Rums include Sailor Jerry, Foursquare and Kraken Black Spiced Rum. Of course, each brand’s blend of spices is a secret but it usually includes some or all of vanilla, clove, sugar, cinnamon and nutmeg. Some of the well-known fruit-flavoured Rums include Cristal Limon from Ecuador and all sorts of flavours from Barcardi and Cruzan (British Virgin Islands) such as banana, mango, coconut and lime. There is also Ron de Miel, a honey-flavoured Rum from the Canary Islands.
Strengths of Rum
Standard strength Rum has an alcoholic strength of between 35% and 45% abv. Above this and the Rum is classified as over-proof and can be as high as 75% abv (or 150 Proof). Two of the best-known over-proof Rums are Wray and Nephew from Jamaica and Don Q 151 from Puerto Rico.
Colours of Rum
This is the most basic and the most often used method of classifying Rum and can be split into the following categories. However, this is not really the best method of classification as Rums can easily be coloured with caramel.
White Rum – also known as Clear, Silver, Crytal, Blanco and Plata, these are mostly un-aged rums. These tend to have little flavour and a general sweetness and are often used as the base for cocktails or punches. However there are exceptions such as Botran White Rum from Guatemala which is aged for a short period in oak barrels, which mellows the rum, and is then charcoal filtered to remove the colour.
Golden Rum – Also known as Amber or Oro in Spanish speaking regions. The colour in Rum comes from the interaction of the spirit with the oak barrels – this is the way it occurs naturally. The barrels used are usually charred oak barrels that have previously held Bourbon Whiskey. However Rum can quite easily be coloured by adding caramel. They have more flavour and and are stronger tasting than light rums. Quite often drunk on their own.
Dark or Black Rums – Again the Rum can take the colour from careful and long ageing in heavily charred oak barrels but can also (unscrupulously) be coloured with caramel. These tend to have flavours of spices, molasses and caramel and are quite often drunk neat and used in cooking. Gosling’s Black Seal Rum from Bermuda is a good example.