All Things Demerara Distillers Ltd — Master Distiller Shaun Caleb On the Record

In late 2019 I visited Guyana as the guest of Demerara Distillers Ltd (DDL), makers of El Dorado rum and home of the historic Port Mourant, Versailles and Enmore wooden stills. I came away with an enormous quantity of material about the distillery and Guyana’s rum history to share.

Thus far, I’ve published:

During my visit, I also spent many hours over three days with Shaun Caleb, Master Distiller and Chief Production Officer of DDL. We had many in-depth conversations ranging from flavor science to distillery operations and rum history.

I won’t say I’ve saved the best for last, but I believe you’ll find the following interview quite compelling and filled with behind-the-scenes details.

Matt Pietrek: What is your formal title and scope of responsibilities at DDL?

Shaun Caleb: As of March of 2019, I’m the Chief Production Officer. That covers both the liquor as well as the non-liquor side of the business. DDL is a group of companies that’s diversified across a wide variety of products and services.

My focus is entirely on the production facilities, which covers our juice production, both packaged and bulk, our soft drink production. We also bottle Pepsi and their line of products under franchise, in addition to our line of local and our own licensed brands of drinks as well as mineral water and other products; but that’s on the non-liquor side.

On the liquor side, I cover the entire suite of production from distillation to aging to blending and bottling. Thus, I see the entire chain of how the magic become reality.

Matt Pietrek: Rums from countries like Jamaica and Martinique are known for their distinctive flavor profile. What are the defining characteristics of Guyana rum or Demerara rum for you?

Shaun Caleb: Demerara rum has very unique characteristics in terms of its aromas, its flavor profile, and its mouthfeel. In terms of the aromas, and to an extent the flavor profile, there’s a heavy presence of fruity and floral aromas and flavors. Those can cover a very wide spectrum. If you imagine greener type shrubs and the bloom that come from those. Or perhaps a lush garden. On the fruitier side, they can vary all the way from berry to a stone fruit to a tropical fruit with a bit of a citrus hint. Whatever kind of fruity or floral influence you’re looking for in your rum, we probably have something along those lines.

Matt Pietrek: Some people have traditionally described Demerara rum as having a smokey characteristic. What’s your take?

Shaun Caleb: We describe it slightly differently. There is a pronounced minerality that runs through all of our rums that we believe comes from the water. Our water is sourced from local ground water, which is at a very high water table level. Because of its proximity to the ocean and the river it tends to have an exchange of a lot of mineral content. For example, sodium, magnesium, and iron in particular are very high in our waters. Even at the point where we extract them for demineralization, there is still unctuous presence of those minerals. That carries through in our rums, giving an almost salt caramel effect because there’s definitely flavor, but there’s that bit of minerality behind it as well.

Of course, there’s smokey flavor as well, but that tends to be more dominant in our rums blended with one of our heritage wooden pot stills.

Matt Pietrek: DDL’s known for their unique collection of historical stills. What are the challenges in keeping them running?

Shaun Caleb: Because of the age of those stills, oftentimes the parts are worn, whether they’re made of metal or wood. We try our best to have weekly and monthly checks. Plus, we have two scheduled comprehensive maintenance programs every year where do a deep dive into the stills and do as much maintenance work as is required. It is a challenge.

For instance, one might expect that the copper components of our Diamond Coffey stills would certainly wear over time. Or for our double wooden pot still, the wood would see some amount of warpage over decades of use. But by ensuring that with each maintenance we do whatever cleaning and reinforcing is necessary to keep it as tight and well-functioning as possible, we’re able to keep it going from batch to batch, crop to crop, year to year.

Matt Pietrek: Today in the distillery I saw some of the scaling that occurred on the copper plates of one of the Diamond Coffey stills. I learned that you can’t run them almost continuously the way newer stills are. Can you share more about how you manage the older heritage stills as compared to the newer stills?

Column still scale at DDL, Guyana

Shaun Caleb: Demerara-sourced molasses comes with a significant amount of ash content. That’s because of the legacy of manual harvesting through which a lot of soil and silt get deposited onto the cane and find their way into the molasses. In addition, because of how sugar is crystallized using limestone, one might imagine that the limestone combines with the mud and ash to form what we call a cake or a scale. In the distillation column temperatures are very elevated and at those temperatures the cake hardens.

In order to prevent it from getting too hard or from building up in the columns, thus preventing effective distillation, we have a program of stopping all the different stills at different periods.

Our most gentle Coffey still, we stop every six to seven days. Another, we stop after three weeks. We sometimes may get to four weeks. We sometimes may have to stop before. We factor that into our production schedule so that we aren’t compromising a need for maintenance for the sake of production. It is a built-in part of our program; our cleaning crews are ready whenever that day comes.

It works like clockwork because you see the change in efficiency. It’s very dramatic. Once we observe it, we confirm the cleaning will take place. But of course, it has already been scheduled. Come 7:00 a.m. the following morning the cleaning crews are ready to work.

I distinguish those older stills from the new still that we installed in 2010. We operate the column that extracts the alcohol from the spent wash under vacuum.

That’s the new multicolumn. The MPRS: multi-pressure rectification still. The first column operates under eighty-five degree Celsius, which was found to be the temperature at which the scale forms and harden substantially. While some of that scale will still settle out of the fermented wash, it isn’t allowed to harden. It’s in a much softer state. The stills can run for a much longer period, months in this case. When we do stop, a hose with water can wash out the stills rather than having to manually chisel out hardened cake. It helps to preserve the still’s life.

Matt Pietrek: How much of DDL’s distillate is pot distilled, versus traditional two-column, versus multi-column?

Shaun Caleb: The pot still is a small portion of our annual production. We plan to run them roughly 260 days a year in total, among all the pot stills. We sometimes run them a bit less depending on if more substantial maintenance is required. But we certainly will see more than 210 days a year of operation.

For our light rums, we run the stills for about 300 to 310 days. Some years it’s up to 330 days of production. Among the older column stills, they run between 260 and 300 days in total on an annual basis. All the stills get a fair bit of action. However, with the older stills, those 300 days are divided among the various stills. Sometimes we only run one Coffey stills. There are times we only run one Savalle still. But together they typically rum about between 260 and 300 days per year in total.

Matt Pietrek: I assume the Versailles and the Port Mourant pot stills run less often are used a fairly small percentage of the overall time.

Shaun Caleb: That’s correct. But because of the heavy-bodied nature of those rums a small percentage is sufficient for the blends.

Matt Pietrek: What are some of the innovations you want to bring to DDL’s rum making?

Shaun Caleb: I’ll start by highlighting some changes in approaches we’ve made. We’ve always had a rigorous way of defining how the stills should be run. What we’ve done over the last decade is to bring an understanding of flavor chemistry and tying that to the nature and operation of the stills. Thus, if we want to make a tweak to the still based on sensory profiles, we can start from an understanding of the fundamental makeup of the product and where we think the stills can be adjusted to cause the change we’re looking for.

That has been very successful in making our quality control far more rigorous and consistent in delivering results. We’re building on our knowledge of flavor chemistry that we have built over this time.

Matt Pietrek: What are some of the more interesting innovations since you came to DDL? What’s been the most interesting change in distillation technique since you’ve started?

Shaun Caleb

Shaun Caleb: Apart from what I just mentioned in terms of marrying the flavor chemistry, we’ve also brought a huge focus on efficiency without compromising the quality or character of what we do.

I can give you a simple example. We’re able to increase the amount of alcohol we get from our molasses by doing very clearly defined tweaks to our fermentation process. The disadvantage is that sometimes we get a very good batch following a pretty standard batch, so we see our columns receiving different strengths in the alcohol feed. While that seems good, the distillation column might see a poor result because it would have been set and balanced on one alcohol percentage, then suddenly it’s seeing a higher amount. It gets disturbed.

Recognizing that, we have standardized the amount of alcohol we feed to the column by adjusting each batch of fermentation. What the still sees, regardless of what happens at fermentation, is consistent. By doing this we’ve achieve further increases in the distillation end as well. Overall, we have seen both our fermentation and distillation plants giving us efficiencies of 98 and 99.5 percent, respectively, for the most efficient stills.

Matt Pietrek: Some Caribbean rum producers are experimenting with using small amounts of cane juice or cane syrup as part of their rum making, in part to support the local cane industry. What are your thoughts on this and molasses sourcing in general?

Shaun Caleb: Fermenting cane juice is practical only at a very small scale. I think once you get to the scale of production that DDL is at, it’s difficult because of the difficulty in preserving cane juice and our relative lack of proximity to a continuous fresh source.

In terms of cane syrup, we have explored that possibility. In fact, recently three of our sugar estates were closed, we partnered with the special purpose unit set up by government to divest those estates so as to keep them as a going concern. They partnered with us to start the factories. We suggested to them the idea of evaporating to make cane syrup so that we get as close to a high-test molasses. We tested that in our production operations. It was quite successful.

We’re now talking with the local sugar corporation to do this again on a smaller scale. While sugar is going through tough times because of the world market price, we want to work with the sugar industry to support their survival. If most of their production can produce high-test molasses or evaporated sugar syrup as opposed to sugar and molasses, that’s something we’re preparing for. It helps us but also helps the sugar industry survive.

Matt Pietrek: What are some of DDL’s recent innovations in waste management?

Shaun Caleb: Waste management is extremely important to us. It always has been and is even more important these days. Starting with our carbon dioxide plant in 1986, to our 2010 biomethanization plant, we’re now refurbishing our entire plant. We have taken them out of operation to do substantial refurbishment work. Replacing and changing out components to bring it back into operation with the hope that we can extract even greater efficiencies.

Beyond that, we are looking at secondary treatment methods. The intention there is twofold. One is to see if there’s further energy potential that can be harnessed by focusing on the substantial amount of solids separated out from our waste. Second, from the digester effluent that’s treated in that first stage, there are technologies now that are more effective in further treating it to both reduce the amount of the chemical oxygen demand, as well as harvesting even more biogas that we can consume for steam generation.

Matt Pietrek: How much of your current power needs are satisfied by your biogas?

Shaun Caleb: I can tell you that prior to the point where we went down from operation, we were able to get 55 percent of our energy for steam generation from biogas. You mentioned power, and that’s important because even though the biogas isn’t yet sufficient to replace 100 percent of our steam generation demand, there is also potential on the power generation end that we want to explore. We are self-sufficient in that we generate our own power. All the resources we need, except molasses, are generated right on our premises.

We were the first company, not just distillery, but first company in Guyana to pilot the use of liquefied natural gas for power generation. We have converted our generators to consume 60 percent liquified natural gas, which is then re-gasified before combustion, and 40 percent diesel oil. That has been quite successful. In this new era of power generation using LNG as well as diesel, we expect to reduce our carbon footprint by 20 percent, as well as reduce any particulate matter that is generated through the stack by over 40 percent.

Matt Pietrek: High ester rums are a hot topic amongst enthusiasts. Tell us about DDL’s high ester process including the fermentation and distillation parts.

Shaun Caleb: Our high ester process is one we seldom talk about because it’s not yet something we have in the market with its own identity. But if you may peek behind the curtains, our process is different from what you might find elsewhere. Our focus is solely on creating a rum with a profile that, apart from esters, is pretty normal, but also has substantially higher esters than you can find elsewhere.

By that I mean an ester content approaching 10,000 parts per million. [Note: this is equivalent to 1,000 grams/hL AA, which is how Jamaican rum esters levels are reported.]

We ferment over a period of months and use special sources of carbohydrate. There are a number of local fruits used in the fermenting mixture that generate a high amount of acidity. We then spike that with a special mixture we create on site. With that special mixture, the acidity and the alcohol react to produce the high amount of esters, up to 10,000 parts per million.

Matt Pietrek: You mean of ethyl acetate.

Shaun Caleb: Ethyl acetate, yes. It’s unique in that you get a single peak that towers above every other part of the profile.

Matt Pietrek: If you were to look at a gas chromatograph (GC) analysis?

Shaun Caleb: That’s right.

Matt Pietrek: Do have a special still for distilling this high ester rum?

Diamond High Ester still at DDL, Guyana

Shaun Caleb: We have a special John Dore double retort copper still used for distilling the higher ester rum. Copper is a useful surface for distillation because it’s active in the esterification process. It helps ensure the esters produced in the fermentation process are given preference and produce even more. The copper acts as a catalyst in the distillation process. We then distill, focusing more on the heads portion of the distillate, which allows us to capture that very high ester content, but without a very big tail as well. In that way it’s unimodal. Just the esters have a very high peak.

From there we dilute, as we do all of our rums, to barreling strength and it goes into barrels.

Matt Pietrek: Can you share if any El Dorado products have some of this rum in them?

Shaun Caleb: I can say that the El Dorado 50th anniversary release rum contained a very small percent of the Diamond high ester rum, which was aged for 33 years. A small pour of that rum in your glass just fills the entire room with just delicious essences.

Matt Pietrek: Can you tell me about DDL’s traditional use of caramel in rum making?

Shaun Caleb: We spoke previously about your research into the West India Committee, and the blue books that were produced annually for the various territories. It piqued my interest because I recall consulting secondary sources that made references to some of the historical rum export stats. Those stats showed that a substantial amount of the rums exported in those days were colored with caramel prior to dispatch. And so coloring rums with caramel was historically a part of how many of the rums were supplied. The practice of doing so continued for all those decades over a century.

I also mentioned to you that in a way, aging rum here at DDL started as a bit of an accident because of having surplus barrels. Due to changes in trade relationships, as well as an era when Guyana started to command its own resources, we were empowered to explore brands. So, when we were challenged to create a blend, the rums that our chemists drew primarily from available rums that were aged with caramel.

Matt Pietrek: Aged with caramel in the barrel?

Shaun Caleb: In the barrel. That tradition continued for at least a decade. It was only in 2004, and for a different reason, economics essentially, that we wanted to experiment with a new way. Caramel is an added cost and there is a capacity limitation in caramel. So, if the brand grew exponentially would we be able to supply caramel to maintain this tradition?

Well, what if we tried to age without caramel? How would the rums come out? It was in 2004 when the company set about its first expansion in barrel warehouses; in purposely setting aside more rums for aging in fresh Bourbon barrels rather than recycled rum barrels and building new warehouses for the increased barrel holding. At that point we explored whether rums aged in new ex-bourbon cask two years in bourbon and without caramel, could work for us. The thought process was to see if the extractive processes, the various reactions that take place in the barrels, the caramelized sugars and so on, would work.

We use charred barrels, typically char three. Again, the thought process was to see if that would be sufficient to give us a similar character of rum that we have traditionally been known for.

We have found that there isn’t a substantial difference, or at least that difference can be controlled. More and more we are moving away from aging rums with caramel to aging rums in fresh wood. This is a direction that we want to go.

Matt Pietrek: What’s your approach to distilling in order to make the right palate of distillates available to your master blender a decade or more into the future?

Shaun Caleb: For each distillate we have a set and defined number of flavors we expect to find. In most cases, we also define flavors we consider undesirable. It doesn’t mean that it’s unpalatable, it means that it is not a typical part of the makeup. We also define the gas chromatograph composition that’s typical of each rum distillate, so every batch is measured against the standard composition profile.

For example, if I’m distilling a rum from which I expect typical notes of a bit of creamy chocolate, with hints of coconut, but not too much, and I instead find a bit of grassiness coming along with it, then I consider grassiness undesirable. Again, going to the flavor chemistry approach that we take, we can identify which components are resulting in that via the gas chromatograph.

Then we change the operation of the still to reduce the presence of those components and shift the product back to have a prominent presence of only the desirable notes. It’s a very intensive process and requires constant attention. But by aligning the focus of the distillers and junior distillers, ensuring that we focus on sensory profile and gas chromatograph composition, we’re able to keep the product consistent in a much more reliable way.

Matt Pietrek: When you make distillation choices such as which still to use and how much to make with it, how far do you project into the future to ensure you have enough for your blenders to work with?

Shaun Caleb: We project twelve to fifteen years into the future. For instance, the number of barrels we are putting down this year, just to cater for El Dorado 12 and El Dorado 15, is more than five times what we currently consume. Our projection tells us that, based on our marketing team’s expectation of growth.

Every year we update that spreadsheet. We look at the total number of barrels required to supply the quantity. Of course, that factors in aging losses and similar factors. Whenever there’s a deficit we plug it into our aging program for the respective year. Then we spread that over the respective months that production is available on the columns stills. Based on that schedule, we then communicate with our suppliers to ensure barrels are supplied on that schedule.

There are years that the marketing team will say “You know what? We have seen tremendous growth on a particular product.” Either they want to replace the baseline from which they estimate growth and/or they may want to increase the projected growth rate. That actually takes place quite often. Whenever that does happen, we revisit the model and go all the way through the entire projection.

Matt Pietrek: How do you deal with a situation where your estimates from twelve years ago haven’t left you with enough of the right rums to meet the current demand for a particular expression?

Shaun Caleb: The process is dynamic, and it’s reviewed every year. But to further cope with that, we build in a certain buffer in two ways. First of all, for every calculation done against those projections, we include a five percent buffer; there’s always room for error. In addition, we review the trends of the past three years and periodically decide to include what we call stocking up.

A few years ago we saw El Dorado 12 just shooting up. In that case, we decided that in addition to what the projection called for, we also stock up a certain number of thousands of barrels in addition to the usual barreling program. If there’s ever a case where growth was faster than we thought in our wildest dreams, at least we have two ways of building buffer and additional stock.

Matt Pietrek: Yesterday we talked about your typical angel’s share and I found it surprisingly small. What is your typical angel’s share and how do you achieve it?

Shaun Caleb: We have come down from between 11 or 12 percent in the worst times, to now between five and seven percent. There are few batches that might see eight or nine percent, but those are exceptions.

Uitvlugt aging warehouse, Guyana

We’ve done that by focusing on better barrel management as well as by using fresh casks, certainly for rums that will be aged for a longer period. We expect the barrels to be in a better condition coming into the facility. That has helped ensure there’s less loss through the barrels themselves. In addition, about 15 years ago, as part of our experiments to reduce our angel share, we found that reducing the aging strength from 84 percent on average to 70 percent was very useful.

It made sense scientifically because our average humidity is about 70 percent, and 70 percent happens to be that point where the preference for alcohol volatility over water is substantially more. By trying to align our alcoholic strength in the cask with the humidity, we have found that we have brought down the drop in strength and loss of alcohol substantially.

So those are the two things: Better barrel management and aging at a more sensible strength given our warm climate.

Matt Pietrek:  I would imagine that over a short time period you’d spend more money for additional barrels. But over a longer time period and factoring in compounding you’re saving a substantial amount.

Shaun Caleb: Right. Remember too that with the ambitious growth plans for El Dorado, it works towards our purpose because the additional barrels also give us the additional volumes we’re looking for.

Matt Pietrek: If you could make one rum blend, call it the Shaun Caleb blend, and it was the only rum you had on a desert island, what would the specifics be? What stills? how long would it be aged? All the details.

Shaun Caleb: For me, our heritage stills are unique. Not only because of their place in history and because they’re the only stills of their kind, but also because the products they make are truly unique and delicious in a way that every consumer wants.

The flavors from the EHP Coffey still, aged for a long period of time become so soft, so delicate, so developed, that it just engenders a deliciousness that is very, very difficult to match. I would start there because I like a bit of body. I certainly like that bit of smokiness that comes from the double wooden pot still. A small percentage of that to me must be present.

Shaun Caleb

I would finish with one of our medium-bodied rums from the Savalle still. There is one with a particular almond note and just a hint of the sweet aromatic notes you’d expect from a molasses distillate.

The combination of those three, aged for a long period almost reminds me of marzipan. I can just imagine a bit of sweet, a bit of nut, coming with a bit of smoke from the pot still, with the bit of fruit from the wooden Coffey, aged for a long time so that they all weave seamlessly into each other.

I would make a 21-year-old, or an 18-year-old at least, blended with those three. That will be the perfect one to sip on.

Matt Pietrek: A similar question. If you had to choose only one still, and aged rum from it for ten or fifteen years to make your desert island rum, which would it be?

Shaun Caleb: The double wooden column still, the EHP.

Matt Pietrek: Who are some distillers whose approach you particularly admire?

Shaun Caleb: Apart from my predecessor George Robinson who I worked for five years directly before myself assuming the Master Distiller role, I tend to look less at personality and more at approaches. Particularly because of exposure to the West Indies Rums & Spirits Producers’ Association (WIRSPA) which has been very good at organizing technical seminars and technical committee meetings where distillers around the Caribbean meet and share experiences.

I’ve been able to learn not only what other distilleries do to achieve the best at what they do, but also how they problem-solve. Sometimes useful insights are gleaned that filter into how we approach various problems. I wouldn’t want to single out anyone except my predecessor, but I’ll say the Caribbean fraternity of distillers are being fostered in building and sharing information and knowledge.

My rather intensive effort to document Demerara Distillers Ltd. wouldn’t have been possible without the help of several people. Huge thanks again to the team at DDL for spending so much time with me in Guyana, as well as fact checking afterwards.

Cocktail Wonk, Jason Bhojedat, and Shaun Caleb

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