What is Rum? The Complete Guide

What Rum Must Be Made Of

Rum is a distilled spirit whose base ingredient must come from sugarcane. That sounds simple — but the legal details vary widely depending on where the rum is produced and where it's sold.

The European Union regulation (EC 2019/787) defines rum as a spirit distilled from sugarcane-based raw materials at less than 96% ABV, bottled at a minimum of 37.5% ABV. Crucially, the distillate must retain the sensory qualities derived from its raw materials — which is why rum can't simply be distilled to neutral spirit and called rum. The EU also sets a maximum of 20 grams of sugar per litre that may be added to the finished product without requiring a different category label. Anything above that threshold must be labelled differently (e.g., as a "rum liqueur").

The United States follows a similar logic. The TTB defines rum as a spirit distilled below 95% ABV from fermented sugarcane juice, syrup, molasses, or other sugarcane by-products, bottled at a minimum of 40% ABV. The key phrase: less than 95%. If you distil higher, you get a neutral spirit — vodka territory — stripped of the aroma compounds that make rum taste like rum.

Then there's AOC Martinique — the world's strictest rum appellation. Rhum Agricole from Martinique must be made exclusively from fresh sugarcane juice (not molasses), distilled on a column still, and produced within the AOC's geographical boundaries. It's the wine-appellation approach applied to spirits.

A related edge case: Cachaça, Brazil's national spirit, is also distilled from fresh sugarcane juice. Legally it's classified separately from rum in Brazil, but internationally it's often grouped under the rum umbrella.

Sugarcane as the Foundation

Every rum starts with sugarcane — but which part of the sugarcane defines the style. There are three main raw material families:

Molasses is the thick, dark syrup left over after sugar crystals have been extracted from cane juice. It's storable, shippable, and available year-round — which is why the vast majority of the world's rum (estimated 95%+) is made from it. Molasses-based rums range from light and neutral to deeply complex, depending on fermentation and distillation choices.

Fresh sugarcane juice ("vesou") is pressed directly from the cane and fermented immediately. It's alive, seasonal, and highly perishable — distilleries must be located next to the cane fields. The result is Rhum Agricole: grassy, floral, and terroir-driven. Martinique is the heartland, but Guadeloupe, Haiti, and Mauritius also produce cane-juice rums.

Sugarcane syrup ("sirop de batterie") is a middle ground: cane juice that's been partially cooked down for preservation but not refined into crystallised sugar. It retains more of the fresh-cane character than molasses while being more practical to store. Some distilleries in Guatemala, Mauritius, and Madeira use it.

One important note: not every sugarcane spirit is called rum. Cachaça (Brazil), Clairin (Haiti), and Aguardiente de Caña (various Latin American countries) have their own legal definitions and cultural identities.

How Rum is Made

The journey from sugarcane to spirit follows three essential steps: fermentation, distillation, and (usually) ageing. Each step is a creative decision point — not just a technical process — and the choices made here determine whether the final rum is light and clean or heavy and complex.

Fermentation is where flavour really begins. Yeast converts the sugars in molasses or cane juice into alcohol, but also produces hundreds of aromatic compounds — esters, aldehydes, and organic acids that will later define the rum's character. Short, controlled fermentations (24–48 hours) produce lighter, cleaner spirits. Longer, wilder fermentations (up to two weeks, sometimes with dunder or muck pits) create the intensely fruity, "funky" profiles associated with Jamaican rum.

Distillation concentrates the alcohol and selects which aromas make it into the final spirit. Pot stills (batch distillation) produce heavier, more flavourful distillates rich in congeners. Column stills (continuous distillation) yield lighter, higher-proof spirits. Many distilleries use both, blending pot and column distillates for complexity. The critical point: rum must be distilled below the threshold where it becomes a neutral spirit, preserving the character of its raw material.

Ageing adds colour, texture, and a third layer of flavour. Fresh distillate ("new make") goes into barrels — typically ex-bourbon American oak, but also ex-sherry, ex-cognac, or new oak casks. Over time, the spirit extracts vanillin, tannins, and caramel compounds from the wood while undergoing oxidation that softens harsh edges. More on ageing in the dedicated section below.

Think of the production chain as a series of creative decisions: Raw material → Fermentation → Still type → Barrel choice → Climate → Blending. Each variable is a dial that the distiller turns to shape the final product.

Rum Styles, Origins & Labels

Walk into a bar and someone will tell you "dark rum is strong, white rum is light." That's a myth. The colour of rum is one of the least reliable indicators of its character. Caramel colouring can make a young rum look old, and charcoal filtration can make an aged rum look clear.

Still type matters more than colour. Pot still rums tend to be heavier, fruitier, and richer in congeners — think Jamaican, Guyanese, and Barbadian rums. Column still rums are generally lighter, cleaner, and more delicate — think many Cuban-style, Trinidadian, or Dominican rums. Many premium rums are blends of both.

Cultural markers in the name tell you something about heritage. "Rum" (English-speaking Caribbean) often signals a molasses base, pot-still heritage, and a tradition of high-ester styles. "Rhum" (French Caribbean) typically means Agricole — fresh cane juice, column still, and terroir-forward character. "Ron" (Spanish-speaking countries) often indicates lighter, smoother profiles with longer ageing traditions. These are tendencies, not rules.

Additives and transparency. A significant number of rum producers add sugar, vanilla, glycerol, or other flavouring agents to their finished product — often without disclosing it on the label. This practice is legal in most markets but controversial among enthusiasts. The RumX community independently tests rums for added sugar and publishes the results, helping you make informed choices.

Barrel Ageing Decoded

Ageing is where rum develops its deepest complexity — but it's also where marketing most often misleads. Two identical barrels of rum, aged for the same number of years in different climates, will taste completely different.

Tropical ageing (in the Caribbean, at 25–35°C year-round) is intense. Heat accelerates the extraction of wood compounds and speeds up chemical reactions. But it also means a much higher "angel's share" — the portion of spirit lost to evaporation each year. In the tropics, distilleries lose roughly 6–10% of their barrel volume per year. A 12-year tropically aged rum may have lost over half its original volume.

Continental ageing (in Europe, at cooler, more variable temperatures) is slower and gentler. The angel's share drops to roughly 1–2% per year. This means more liquid survives, but the wood interaction develops differently — often yielding more subtle, oak-driven complexity. Some producers (like Foursquare) age in the tropics first, then finish in cooler climates.

Age statements can be misleading. Unlike Scotch whisky, there's no universal standard requiring the stated age to reflect the youngest component in the blend. Some countries allow solera systems where rums of vastly different ages are blended, and the label may reference the oldest component. A "23-year-old" solera rum may contain spirit as young as 3 years. Always check whether the age statement refers to a minimum, maximum, or average.

ABV and Proof. Most rums are bottled at 40% ABV (the legal minimum in most markets). "Proof" is simply ABV multiplied by two in the US system, so 40% ABV = 80 Proof. Overproof rums (typically 50–75% ABV) and barrel-proof / cask-strength bottlings (whatever ABV the rum reached in the barrel) deliver more concentrated flavour and are popular among enthusiasts.

History & Responsibility

You can't tell the story of rum without talking about colonialism and slavery. The two are inseparable. Sugarcane cultivation in the Caribbean was built on the forced labour of enslaved Africans, and rum was both a product of and a currency within the transatlantic slave trade.

The triangular trade connected Europe, Africa, and the Americas in a brutal economic loop: European goods were traded in Africa for enslaved people, who were transported across the Atlantic (the "Middle Passage") to Caribbean sugar plantations. The sugar and molasses produced there were shipped back to Europe or New England, where some was distilled into rum — which was then traded again for more captives. Historians estimate that roughly 12.5 million people were forcibly embarked on slave ships between 1526 and 1866, of whom approximately 10.7 million survived the crossing.

When Britain abolished slavery in 1833, the government paid £20 million in compensation — to the slaveholders, not to the people who had been enslaved. The formerly enslaved received nothing. Many Caribbean economies remained dependent on sugar monoculture for decades afterward, and the economic legacies of colonialism persist today.

Modern rum culture is increasingly reckoning with this history. Questions that matter: Who profits from the rum in your glass? Are workers on sugarcane plantations paid fairly? Is the supply chain transparent? Some distilleries are actively addressing these questions; others still trade on romanticised colonial imagery. As a rum drinker, you have the choice to support producers who engage honestly with their history.

Discovering Rum with RumX

Start with style contrasts, not price. Try three rums side by side: a white rum (unaged, clean, showcasing the raw material), an aged rum (barrel-influenced, vanilla and oak), and a Rhum Agricole (grassy, herbal, terroir-driven). That triangle will teach you more about your own preferences than any tasting note.

Read rum like data. Every bottle tells a story through its label — if you know what to look for. Track: raw material (molasses vs. cane juice), distillery, still type (pot vs. column), age, storage location (tropical vs. continental), ABV, and whether sugar has been added. Over time, you'll build an intuition for what you like.

Use community signals. The RumX community has rated thousands of rums. Use the Charts to see what's trending, check Best Rums for community favourites, and browse New Arrivals to discover what's just been released.

Improve your tasting skills. If you want to go deeper, read our guide on How to Taste Rum — it covers nosing technique, tasting vocabulary, and how to identify specific flavour compounds. And whenever you encounter an unfamiliar term, the Rum Glossary has you covered.

The motto: not "dark is better" or "expensive is better" — but "fitting is better." The right rum is the one that matches your palate, your mood, and your curiosity.