The Gargano Classification: how to distinguish great rum

My classification was inspired from a reflection on how rum consumption in Italy has evolved between the early 90s and the first decade of the 21st century. 

Italy was the first country in Europe where kids born in the 70s experienced the 'Rum Movida' of the early 90s, following a boom in the popularity of Cuba Libre made with Havana 7, which became one of the most widely consumed long drinks. Riding the wave of the rum craze, Velier began importing what at the time were little-known rums from all over the Caribbean, including Caribbean Club, Brugal, Barcelo, Barrilito, Santa Teresa, Matusalem, El Dorado, Bally and many others. Then, in the late 90s, Mojito came on the scene, triggering rum's transformation from the Cinderella of the alcoholic world into the trendiest spirit. 

At the end of the last century, Italy was the only country in Europe where people could find and enjoy rums from all across the world. In the rest of Europe, consumption was still heavily influenced by traditional habits, with each country drinking rum from the Caribbean islands that were historically connected to it, i.e., places that had once been English, French or Spanish. 

It was only between 2007 and 2008 that rum consumption in Europe began to expand beyond these traditional regions. However, just as Europe started showing increasing interest in different rums, the spirit's popularity in Italy began to wane. 

Unlike whiskey consumption, which evolved from blended, to single malts, to peaty, to cask strength, rum has never gone through a similar process. 

Why? Why was Italy, the first country to see a surge in rum consumption, starting to lose interest in it? 

Also: could this happen in the rest of Europe as well? That is, would interest in rum also wane in Europe once the fashion was over, just as it had in Italy? 

I started answering these questions in 2010, when I got in touch and eventually became friends with Charles Gordon, the 80-year-old visionary owner of William Grant's and a pioneer in selling Pure Single Malts. 

Back in 1964, Charles had been the first one to bottle Glenfiddich, which - like any other single malt - until then had been used as an ingredient in blended whiskey. He thus single-handedly created a separate category for single malts as opposed to blended malts. 

Charles Gordon provided an eye-opening piece of information when explaining in detail the origin of the definition “Pure Single Malt”: Pure, because it's made exclusively through batch distillation; Single, because it comes from a single distillery and is not a blend; Malt, because it's made just from barley and no other cereal. 

Clearly the decisive element is that Pure Single Malt is 100% distilled from pot stills, i.e., batch stills. 

It's a craft product and, while many aficionados don't regard pot still distillation as a discriminating element between blended and single malts, everyone agrees that Macallan falls under a different category from Ballantines or Johnnie Walker. 

It was on those nights spent discussing with Charles on his boat, the Cindarella, that I was enlightened on something that had been glaringly obvious all along, but had never actually come to the fore: all rums were simply called "rum" – except for agricultural rums, so called regardless of the distillation method. This lack of clarity prevented enthusiasts from easily distinguishing between industrial and artisan products, that is, rums aged on-site at the distillery, worthy of being carefully savored like the best single malts, a great cognac or any other quality spirit. 

Therefore, my classification was essentially developed to distinguish craft rums - rich in different substances besides alcohol - from industrial rums, which mainly contain ethanol. 

This classification only applies to craft rums and is based on distillation method, for some very specific reasons. 

If one were to classify all existing types of rum there would be a huge number of variables to consider; they would need to be differentiated based on ingredients as well as fermentation, distillation and aging techniques, with each of these four areas being divided into several different sub-categories. 

However, all of these variables take a back seat compared to distillation. Even the best ingredients and fermentation technique would see their benefits obliterated by industrial distillation, which mainly extracts ethanol and causes the loss of any non-alcoholic substance from the - albeit excellent - ingredients and fermentation process. 

Let's start by taking a look at each differentiating element to get a better understanding of the number of sub-categories and possible variables at play in the world of rum. 

Ingredients, and of course the terroir they come from, are the foundation of any spirit. In order to explore the different kinds of ingredients involved in the production of rum, we must also consider the different varieties of sugar cane as well as how they are grown.

Sugar cane varieties

There are currently many hybrid varieties of sugar cane, with very few non-hybridized ones. 

Hybridization

Sugar cane hybridization became a common practice in the late 19th century. Hybrids are produced through crossbreeding, with the goal of selecting the plants that are most resistant to disease and climate and produce the most sugar. Sugar cane was in fact originally selected for sugar production, not for making rum. It is only in the last 50 years, on the French islands of Martinique and Guadeloupe, that sugar cane has been crossbred specifically for producing rum rather than sugar. 

The most successful hybrids in the late 19th century were the varieties named POJ 100, 247 B, EK 28. Between 1900 and 1940, the most widely grown rum sugar cane varieties included BH 10/12, B 147, B 47.259 and B 208, first developed in Barbados, and some varieties obtained in Demerara, like D 74, D 109, D 625 and D 1135. All these varieties were then exported to Mauritius, Louisiana, Puerto Rico, Australia, Reunion, Cuba, Jamaica, and many other places. 

Each sugar cane variety is identified with a code indicating its region of origin 

>> Learn more about sugarcane source stations

Wild ancestral varieties

For centuries and well into the 1800s, sugar cane has been grown simply by propagating the stem cuttings from a limited number of wild varieties. 

Today, very few varieties are created by propagating cuttings from wild sugar cane from New Guinea, Indonesia, Southeast Asia and Polynesia. 

One of them is the Créole variety, which has taken on different names depending on the island where it was grown. 

Introduced in the Caribbean and South America during the European conquest in the 16th and 17th centuries, this variety was the only form of sugar cane grown in that region of the globe for two to four centuries, depending on the country. 

Créole sugar cane was grown into the late 18th century. Then, in 1768 Bougainville introduced the Tahiti (or Otaheite) variety into Réunion and Mauritius.  

Differences in farming methods 

Another key difference is the method used to grow sugar cane, which can be organic or non-organic. 

Unfortunately, over the last fifty years chemistry has begun creeping into sugar cane farming to increase production and reduce costs. In many regions - like the French Antilles - sugar cane fields have also been polluted by chemical products used in banana farming, which has largely supplanted sugar cane. In response to this, in recent years there have been attempts to decrease the impact of chemistry on sugar cane farming. For example, Neisson is already producing rum from certified organic sugar cane. By contrast, there are whole regions in the world where chemistry has never arrived, mainly including Haiti as well as several rural areas in South America, Africa, Asia and Cape Verde. 

As ingredients are the basis of any spirit, a healthier, cleaner agriculture will result in higher quality rum. And this is perhaps more important than the sugar cane variety used.  

The basic ingredients of distillation 

Another difference is the type of ingredients used in the production of rum, which can be distilled from:

Pure cane juice, which must be fresh - meaning pressed and fermented as quickly as possible after the sugar cane is cut down;

Jus cuit, cane juice that has been concentrated (12-15%) with a technique commonly used until before World War II. Today, the last and only distillery using jus cuit is River Antoine; 

Syrup, i.e., cane juice at even higher concentrations ( 40 brix ); 

Molasses, that is, what's left of the sugar cane after the production of sugar, which is still rich in non-crystallizable sugar. 

The first three are basically cane juice at different concentrations, obtained from sugar cane used solely for the production of rum. Molasses, on the other hand, is obtained from sugar cane used in the production of sugar, which means variety has a greater impact. All molasses rum is in fact made from varieties designed to produce more sugar and be more resistant to disease and climate. 

Different types of fermentation

Ingredients are fermented in order to turn sugar into alcohol and use their properties to develop substances which will in turn be extracted during distillation, resulting in different types of rum. 

Here, too, there are differences. Fermentation can take place by adding or not adding water; by using wild yeasts, home-grown yeasts that can be used as a starter, or selected yeasts. In addition, dunder (the residues from previous distillations) may also be added. Some fermentation techniques also call for bagasse (woody sugar cane residues left over from pressing) or sugar cane juice vinegar. 

Additional differences are based on fermentation time: today, industrial fermentation usually lasts 18 hours, but it can extend up to 20 days and in some cases even longer. 

Industrial fermentation can be further sped up by using acidifiers not obtained from sugar cane (such as vinegar), nutrients to feed selected yeasts, defoamers, etc. 

Differences in aging  

A major difference in aging is between tropical aging and continental aging. Our classification, however, only considers rum aged in tropical climates. 

This is mainly because, as mentioned, this classification only includes clearly traceable distillery rum, meaning rum where each processing stage can be traced, something that is not possible with rum aged in continental climates. 

In addition, in continental climates conditions are very different from those in the original production regions, and it is essential for authentic, distinctive rums to age in the same climate - and ideally in the same distillery - where they were produced. 

Tropical aging outside the original distillery may be acceptable, but distillery aging is always preferable. We demonstrated this by aging several Neisson casks in different places in the same distillery. As it turned out, the same spirit made from the same sugar cane and fermentation batch, aged in the same type of cask and even in the same distillery in small storage areas only 50 meters apart produced very different rums due to differences in average temperature-to-humidity ratios. This is further evidence that terroir makes a dramatic difference. 

Another aging-related difference is the spirit's ABV at barrel entry. This ranges from 55% up to still proof. Rum was traditionally aged at still proof with an ABV up to 80-82%, because at the time saving casks was a priority. Over the years, barrel entry at 66% ABV became the most common practice. There are also exceptional cases where rum comes out of the still with an ABV below 55% (e.g., Clairin). 

Yet another difference lies in the type of wood the casks are made of as well as their size and condition, i.e., whether they are new or have previously contained other spirits or wine. 

Barrels range from barriques (200 liters) up to 15,000-liter Australian containers. New casks can be selected based on origin, toasting and wood porosity. New casks also require frequently moving the content to other casks, because if rum remained in a new cask for too long, the wood would have too much influence on aging. So transfers need to be frequent at first, keeping the white rum in new barrels for increasingly longer periods in order to "break them in" and gradually age them until they’re ready to age rum from start to finish. 

Traditionally, the most widely used ex-spirit barrels are American oak ex-bourbon, for two reasons: proximity to the US and wide availability at low prices, as bourbon regulations allow barrels to be used only once. More recently, other wood types like French oak (Allier, Tronçais), and in some cases Slavonian oak and Acacia, have become more widely used. 

In addition to ex-bourbon, ex-cognac, ex-calvados and ex-rum barrels (from different rums than the one being aged) are also used. As for ex-wine barrels, options range from ex-red and ex-white wine to ex-fortified wine such as Madera, marsala, and of course sherry. 

Bottling also adds other variables. Rum aged in tropical climates - which evolves and ages very differently compared to rum in continental climates, losing between 6 and 12% in angel's share every year (!) depending on the terroir - can be bottled at cask strength, i.e., the ABV after aging in the barrel, or it can be brought down to 38% ABV by adding water. 

The central role of distillation

As we have seen, if rum were to be sorted based on all possible variants (which each producer can obviously combine in countless ways) there would be a huge number of sub-definitions and it would be impossible to accurately classify all existing rum types. But, as mentioned, all those differences are irrelevant in industrial distillation, which mainly extracts ethanol and leads to the loss of most of the distinctive properties of the ingredients used. 

Of course, there are many distillation methods, but the type of equipment is what makes the biggest difference. 

For this reason, distillation plays a central role in my classification, which is also used for whiskey, cognac, calvados, mezcal. 

Based on distillation, rum can be classified as follows: 

- Rum made from batch distillation using different types of stills (in my classification it’s termed Pure Single Rum, on the same pattern as Pure Single Malt whiskeys);

- “Traditional” rum distilled from Coffey or Creole column stills – broadly identifiable as the so-called agricultural rum made from pure sugar cane juice; 

- Single Blended rum, a unique case in the world of spirits. As some distilleries have both continuous columns and batch stills, Single Blended refers to rum produced in a single distillery by blending different types of rum from both continuous and batch distillation; 

- Ordinary rum distilled from multi-column stills.

There are no major quality differences in the first three categories - Pure Single, Traditional and Single Blended rum. The real distinction is between those and industrial rum produced from multi-columns - two completely different worlds, where the first (Pure Single, Traditional and Single Blended rum) seeks to extract and preserve as much as possible the qualities and properties of the fermented ingredients; the other (multi-column rum) seeks to produce as much ethanol as possible. Regardless of ingredients and fermentation method, multi-column distillation can never result in a product that fully expresses the original quality of the ingredients.

Other characteristics that make for a quality spirit can be seen as consequential, as it's reasonable to assume that distilleries using non-industrial distillation techniques to preserve the original qualities of the ingredients will also take greater care in selecting and processing them. 

This classification of rum into precise categories finally provides rum lovers with a framework to better understand the key differences between industrial, mainstream products and high-quality craft rum, which includes Pure Single, agricultural and Single Blended rum. 

Looking back 5 years ago, I think very few people knew how to tell cheap from great rum. Today, I'm proud to say that my work ultimately contributed to bringing great craft rum to light and giving it the recognition it deserves, as shown by recent developments in the rum market.