Why Does Jamaica Limit Its Rum to 1600 Esters?

Something that makes Jamaican rum so unusual is a particular substyle colloquially known as high ester rum. Most hardcore Jamaican rum wonks have heard that a law prohibits selling Jamaican rum with an ester level exceeding 1600.

Naturally, we might ask: what are ester levels? And why do the Jamaicans cap them?

The answer to these questions —and more— lies below, which I’ve partially adapted from chapters 10 and 20 of Modern Caribbean Rum.

A Brief Bit of Science

Note: I’ve dramatically simplified this section for understanding and brevity.

Every aroma or taste in a distilled spirit comes from various organic compounds present in very minute proportions. Everything we smell—be it a strawberry, burning plastic, rotting eggs, wet dog, or freshly cut grass—is sensed via airborne compounds reaching our nasal receptors.

Most of the organic compounds in distilled spirits fall within several categories, which include but are not limited to:

• Fatty acids

• Alcohols (ethanol, methanol, and higher alcohols)

• Esters

• Aldehydes

• Phenols

While each organic compound contributes to the overall symphony of aroma and flavors, here we’re focused on just esters and one specific ester known as ethyl acetate. It’s by far the most prevalent ester found in rum, and its aroma is described as “fruity.” In sufficiently high concentrations ethyl acetate can smell like nail polish remover or glue.

In laboratory testing, ester levels are traditionally specified in units of grams per 100 liters of absolute alcohol. This unit is typically abbreviated as gr/hlAA, i.e., grams per hectoliter of absolute alcohol. (In such testing, the spirit’s water content is effectively ignored.)

A rum with an ester level of 200 means that 200 grams of esters are present in each 100 liters of rum, without considering whatever water is present as part of the total volume.

Many mainstream rums have esters levels of 50 or less and are considered fairly mild in flavor. Most rums over 100 gr/hlAA have a fairly strong flavor; at 500 gr/hlAA the flavor is quite intense.

Important note #1: Ester levels have traditionally been used as an extremely crude, one-dimensional approximation to flavor intensity. However, there is much more to the story, and chapter 10 of Modern Caribbean Rum is focused solely on this topic.

Important note #2: In the excerpted quotes later in this post, the term ether is used rather than ester. While not technically the same, they can be considered equivalent for our purposes.

A Bit of History

By the late 1800s, Germany’s rum drinkers had quite a love for flavorful Jamaican rum. But at some point, the German government imposed a heavy tax on imported spirits. German blenders circumvented these taxes by importing lesser quantities of the most strongly flavored Jamaican rum and blending it with German-made neutral spirits. The resulting spirit was called rum verschnitt.

In time, certain Jamaican distillers shifted their production to favor rums with ever-higher ester counts intended as a sort of rum flavor concentrate for the German market. In the rum trade, this concentrate was known as German, Continental, and Flavoured rum, as seen in this excerpt from the 1897 West India Royal Commission report:

(Sir Edward Grey) What are German rums?

(Mr. Craig) They are very highly flavoured rums which are used for blending other spirits on the Continent.

(Sir Edward Grey) Do they go to Germany mostly?

(Mr. Craig) Yes, they use potatoes or beet spirit, and flavour it with small quantity of “German” rum and sell it all over the Continent, particularly in Russia, as Jamaica rum.

This so-called German rum commanded a higher price than traditional Jamaican rum intended for drinking. However, British blenders and the drinking public had little use or desire for it at the time.

Eventually, H.H. Cousins, Jamaica’s island chemist, created a technique capable of producing rums with an ester level of 6,000 gr/hlAA. Only a few distilleries, mostly in the Trelawny and Westmoreland parishes, could make such high-ester rums.

Why Cap Esters at 1600?

By the 1930s, Jamaica’s rum market was in dire straits; overproduction was rampant while demand and prices were low. At the time, some of these challengers were blamed on high ester rum production.

There’s an apocryphal saying, “The capitalists will sell us the rope with which we will hang them.” It seems relevant to certain Jamaican distillers selling rum to German blenders who adulterated the rum with neutral spirit for resale as counterfeit Jamaican rum.

A 1933 editorial in the Kingston Gleaner outlined the situation:

As to the high ether rum, that indeed may have helped a few of our estates temporarily, but it has certainly not been of general benefit to the rum industry of this island, and the fact is indisputable that because of the harm wrought by it to the rum industry its manufacture is now discontinued. This high ether rum has been used by foreigners, to the degree of from one to five per cent, as a flavouring for their own spirit which has been sold as Jamaica Rum. The consequence of this has been a marked diminution of sales of ordinary Jamaica rum for flavouring and other purposes abroad; hence an effort is even now being made to remedy this situation. The spirit dealers of England do not hesitate to say that the greatest mistake ever made by Jamaica was to put high ether rum on the market.

A subsequent 1934 Kingston Gleaner item further elaborated on the situation:

Conditions which are regarded as distinctly unfavourable to the rum industry of Jamaica have been created in Germany, in particular, also in Poland and Czechoslovakia, by spirit merchants who blend high ether rum with potato spirits. Hitherto large quantities of high ether rum were made by one or two estates in Trelawny for the trade mentioned above; but the system under which blending is conducted, in Germany for instance, has convinced estate owners in Jamaica that it is not to their interest or that of the island at large that the production of the VERY HIGH ETHER PRODUCT should be continued.

The Rum Pool Steps In

Responding to the overall dire conditions of the Jamaican rum market, an organization of producers (the “rum pool”), was formed in 1932 to coordinate allowed production and practices across all producers. Among the rum pool’s early actions was seeking a legal limit on the ester levels of rum made in Jamaica. The Nov. 15, 1934 Kingston Gleaner noted:

In the Legislative Council yesterday the acting Attorney-General introduced a Bill entitled a Law to Control the Ether Content of rum manufactured in this island:

The object of the Bill is to control the ether content of rum manufactured in the island and it is sought to enact the Bill in order to prevent the indiscriminate manufactured of high ether rum. It is thought that if tie manufacture of high ether rum is not controlled such rum if sold in a foreign market might be used to dilute spirits and the resultant mixture sold as rum to the detriment of the good name of Jamaica rum. The rum manufacturers of the Island have by a self-denying resolution endeavoured to eliminate THE MANUFACTURE of high ether rum.

The eventual law passed was known as The Rum (Ether Control) Act of 20th December 1934 which read in part:

3. No person shall manufacture rum in this Island with a higher ether content than that fixed from time to time by order under this Act.

4. (1) It shall be lawful for the Minister from time by order published in the Gazette to fix the maximum ether content of rum manufactured in this Island. The Minister may from time to time by like order vary the maximum ether content so fixed and may revoke or amend any such order previously made.

The Bill further provides for the seizure and forfeiture of rum manufactured contrary to its provisions. Also, the law as written does not state an actual ester level but leaves it to a government official (“the Minister”) to establish the allowed ester level.

An initial cap on the ester level was set in early 1935 at 1,600 gr/hlAA:

THE RUM (ETHER) CONTROL ORDER, 1935

(Proclaimed by the Governor in Privy Council on the 18th day of February, 1953)

I. This Order may be cited as the Rum (Ether) Control Order. 1935.

2. The maximum ether content of rum manufactured in this Island shall be and the same is hereby fixed at 1,600 ethers.

Jamaican Rum Today

That limit of 1600 gr/hlAA of esters for Jamaican rum is still enforced by Jamaica’s Spirits Pool Association today and hasn’t changed since its 1935 establishment.

Three Jamaican distilleries are known to produce rum at the 1600 gr/hlAA level today:

• Hampden Estate – DOK marque

• Long Pond – TECC marque

• New Yarmouth – NYE/WK marque

For more information on Jamaican rum marques, see this page.

The remaining distilleries can make very flavorful rum but don’t use the process required to make rums at the 1600 level. Too learn more about all of Jamaica’s distilleries, chapter 20 of my Modern Caribbean Rum book has detailed looks at all six, including dozens of photographs.

As noted early, these high-ester Jamaican rums were intended only for blending, not to be consumed by themselves. Nonetheless, such rums have become available to rum consumers via independent bottlers. As you can probably guess, “DOK Daiquiris” and similar contrivances have made the rounds on social media.

Fun fact: You can still purchase rum verschnitt today.

In a future post, I’ll connect what we learned above to a current, particularly beloved Jamaican rum and reveal a few surprises.