Table of Contents
What is a Distillery?
Who works in a Distillery?
The Processes
Sugar extraction
Fermentation
Distillation
Aging
Blending
Compounding
Bottling and labelling
The ingredients
Making Rum in a Distillery
Operating a Distillery in the UK
What is a Distillery?
According to the Cambridge Dictionary, a Distillery is "a factory where strong alcoholic drinks are produced by the process of distilling" which by itself is not particularly helpful. According to the BBC, Distilling is a segregation technique used to separate a component from a mixture. It involves boiling the mixture and then condensing (cooling) the gas so that it returns to its liquid form. By strong alcoholic drinks, it is meant that there is a high concentration of alcohol within the drinks produced. Examples include rum, vodka, gin and whisky. This level of alcohol contrasts with the levels found in beer, which is produced in a Brewery. The UK Government discusses how these high alcohol liquids, often called spirits or liqueurs, are prepared. "Distilled spirits are produced from agricultural raw materials such as grapes, other fruit, sugarcane, molasses, cereals etc."Distilling as a chemical process has been around for thousands of years and there are documents that link this knowledge to ancient Greeks, Egyptians and even to Mesopotamians. Accounts of using the process with seawater, wine, perfume as well for medicinal balms exist over this period. It is believed that Queen Cleopatra knew of the process as well as Aristotle.
The oldest rum company in the world is in Barbados. The Mount Gay Distillery started operating in 1703 and is still in use today. As for the oldest known rum, that award goes to the 1780 Harewood Barbados dark rum. We talk about the distinct types of rum in another Swan Knight Distillery blog post.
If you are interested in looking around a distillery then many distilleries offer tours and some even provide tasting rooms for their products. An effective way to find them is to do a Google search for a "distillery near me" and go from there.
Who works in a Distillery?
Although there is no set definition for the responsibilities of a Head or Master Distiller, it is common for the role to have overall responsibility for the distillery, the people who work in it and the quality and quantity of the products that leave it. Wikipedia suggests that such a role can also be the site distilling expert. The role usually has back-office responsibilities too, such as administration, marketing, finances and the ordering of ingredients. In the UK, it is possible to gain a Master Distiller qualification from the IBD (Institute of Brewing and Distilling) but it is not essential. Each distillery has its own view as to what skills, experience and qualifications are necessary for their Master Distiller to have. It is not unusual for a Master Distiller to have a background in either Chemistry or Engineering. Distilling can be a dangerous business if not done correctly as alcohol is flammable and not all alcohols are safe to drink. As a result, there are significant Health and Safety considerations in a distillery that the Master Distiller is also responsible for.There are various other roles that can be labelled as distillery workers or assistants, depending on the distillery. In addition, the type of spirit being produced will generate other roles within the distillery. For example, in the production of some vodkas and whiskys, there can be large floors where the barley is malted. This process involves soaking the barley, then allowing it to germinate and sprout. The final part of the process is to heat it (known as kilning) where the growth process of the barley is stopped. The workers who look after this process are known as Maltmen.
Generally, distillery workers are generalists who assist the Master Distiller in all of the operational manufacturing tasks, as well as cleaning the equipment and maintenance. These activities can include weighing raw materials into the appropriate tanks, maintaining records, bottling and labelling the finished products as well as packaging bottles, ready for customer delivery.
In addition, if the final product is a blend of other products, then a role known as the Master Blender may exist. This role can exist in almost all types of spirits, but it is most common in whisky and rum production. The primary focus of the role is to ensure the quality of the final blended product and that it remains consistent between production runs. In smaller distilleries, the role may be the same as the Master Distiller as the responsibilities can intersect.
Many larger distilleries offer an onsite shop and sometimes tasting rooms. These are a fantastic opportunity to find out more about the distillery, its history and products. Often there are tours around the facility that can be most interesting and the Tour Guides that run these are another group of distillery workers. The role of the Tour Guide is to educate the public as well as ensure their safety when on the tour around the plant and machinery.
Finally, last but not least, the distillery cat has an important role, managing the rodent population. Particularly in grain based distilleries, the storage of the ingredients can be tempting to rodents. In fact, larger distilleries can have several cats for this purpose. However, it is common to find the cat relaxing in the shop or tasting rooms during the day, perhaps engaging with the public, before going off to work at night. Our distillery cat, Lunar, has most definitely got the "lazing about in the day" aspect of her role nailed, as can be seen in the photo below.
The Processes
Depending on the type of spirit, the number of chemical processes can range from a few through to a considerable number, many with complex interdependencies. For the sake of simplicity, we will focus on the main processes involved in making rum. The diagram below shows the main processes and their order, including three optional processes, depending on the type of rum being produced.
Sugar extraction
All rum starts as extracted sugar from sugar cane, molasses or sugar beet. Sugar cane is harvested and then shipped to a sugar mill, where it is chopped up and crushed. The fluid is then boiled and filtered to increase the sugar content. At the end of several more processes, sugar is produced and a by-product from these processes is molasses, which is used for making rum. In fact, rum came about through the desire to find a use for molasses.
We cover the many types of rum separately, which may be of interest.
Fermentation
The next process is fermentation, and it uses yeast to convert the sugar solution into alcohol. Temperature control is important is it allows the yeast to achieve an optimal output. If the temperature is too hot, then the yeast will die but allow it to drop too low and the fermentation will stall or even stop. Fermentation can take from a day to several weeks, depending on the type of yeast and its characteristics, as well as the volume of the fluid. The outcome is a 5%-10% alcohol liquid, sometimes known as a mash, which is ready for distillation.
Distillation
Distillation is the process of separating one or more compounds with different boiling points from a mixture. In the context of producing rum, this involves taking the mash from the previous stage and putting it into a vessel, called a still. There are broadly two types of still. One is a pot still that often looks like a copper kettle. In fact, some countries call this type of still "kettles". The other type is a column still and are vertical columns with plates at regular intervals throughout the structure. Whichever type is used, the concept is the same. The mash is heated up and as alcohol has a lower boiling point than water, the alcohol turns into gaseous form and rises to the top of the still. Once there, it enters pipework and is then cooled (conceptually by a metal jacket containing running cold water, called a condenser) and, as a result, cools and returns to liquid form. It then trickles down into a collecting tank, or a device called a Spirit Safe. The process can be conducted multiple times (although the alcohol will need to be diluted each time in order for the process to be safe) and the result is how double, triple or more distillation can be achieved. At this point, the liquid (known as distillate) has a much higher concentration of alcohol. Craft distilling uses traditional methods, such as copper kettle stills and natural ingredients whereas Artisan distilling is more focussed on high quality, small batch production methods. Nonetheless, it is not unusual for the craft and artisan distilling descriptions to be used interchangeably.
Aging
This optional process involves taking the distillate and placing it into barrels for a period of time, so that it can pick up colour and flavours from the barrel. As with every process in the manufacture of rum, the type of barrel (i.e. what it was used for previously), the type of wood it is made from and the duration of the rum being in the barrel, makes a significant difference as to how the rum looks and tastes.
Blending
As discussed earlier, blending is the optional process of mixing two or more rums to produce a final rum product. Component rums for rum blends have been carefully selected and quality checked to ensure that their tastes are compatible with each other. For example, it could be that a rum with a woody flavour is enhanced by the addition of another younger rum, whilst simultaneously bringing out other dormant flavours.
Compounding
Another optional process is compounding. This process involves adding additional ingredients to the distillate in a tank and letting the mixture absorb the flavours over a period of time. The result is then filtered to remove the ingredients e.g. cinnamon sticks, so that the resulting spirit contains the flavours from the ingredients.
Bottling and labelling
Although not strictly a chemical process, it is still an essential part of a distillery. This is usually a separate area from the manufacturing and, depending on the size of the distillery, can be highly automated. Labels, on reels, are loaded into the labelling machine and once the bottles have been capped and sealed, they can be applied automatically. Once bottled and labelled, the bottles are ready to be packaged and shipped to customers. The labels on the bottles need to display the ABV (Alcohol by Volume) of the spirit and this is shown as a percentage. In other words, the proportion of alcohol by volume in the spirit. In the United States, proof is used to define the strength of the spirit in the bottle. Proof is twice the value of ABV so 40% ABV rum is 80 proof rum. Another critical area for bottle labels is the UK duty paid stamp. This purple sticker shows that the manufacturer has paid the UK government the alcohol levy defined by law. Like many spirits, rum will last almost indefinitely in the bottle and once opened, may slowly loose some flavour but this will be over a period of several months and possibly years.As can be seen in the various process, there are an enormous number of variables involved, in the quality, taste and colour of the final rum. Everything from where the sugar is sourced and the type of the sugar used, through to how the mash is distilled and any optional processes, combine to produce an enormous range of rums that are fantastic to try. An introduction to the many types of rum can be found in our Swan Knight distillery blog post on the topic.
The ingredients
The secret to producing a high quality rum is, without doubt, the quality of the ingredients used in the manufacture of the rum. Ensuring that the suppliers are reputable and have quality control processes in place, is an excellent starting point. From a sustainability perspective, it is an excellent idea to source locally as it helps the local economy and reduces the emissions from transport. Being able to identify where ingredients are originally from and review the supply chain from that location to your door is highly beneficial. Not only does it highlight any potential risks, but it also permits an assessment of the green credentials of the intermediary parties in the supply chain. Such reviews should apply to everything in relation to the distillery and therefore plant machinery, transport, barrel selection and services such as water and energy should all be within scope. However, this has must be balanced against getting the best possible product produced at the most affordable price for customers. It is for this reason that it can take a considerable time to bring a product to market. For example, when we set out to make Swan Knight Distillery golden spiced rum to be the absolute best sipping rum, it took a considerable time to get the recipe and the resulting suppliers right. This is not something that can be rushed but the recent silver award at the London Spirits Competition was a great reminder that all of the hard work and attention to detail was well worth it.
Making Rum in a Distillery
As can be seen from the preceding sections, making rum in a distillery is a complex activity. Everything from accepting raw materials onto site, managing all of the chemical processes and finally storing or shipping bottles to customers, takes a considerable amount of space, people and machinery. Although this blog post has focussed on the physical aspects of making rum, it is important to point out that production capacity must broadly match the demand from customers. Too much capacity and the distillery will become loss making with the inevitable consequences for all involved. Too little capacity and customers will be disappointed, leaving money and bad reviews in their wake. Therefore, forecasts from sales and marketing should inform how much production should be planned for. That is not say that no thought should be given to eventualities or risks. For example, what happens if the still requires immediate and extensive maintenance? Having plans for the most likely risks whilst ensuring that the production output hits the sales and marketing targets, is what makes the role of Master Distiller so challenging but hugely rewarding.
Operating a Distillery in the UK
There are a substantial number of aspects to operating a distillery in the UK and below we describe some of the biggest areas. Firstly, there is all of the UK laws and compliance. This is a significant area as there are numerous laws from production, warehousing and duty payments through to personal and wholesaler licenses. Liaison with multiple local government and national government agencies can make this an area that requires constant attention. It is worth noting that duty is liable on produced alcohol, regardless of whether it has been bottled or not. In other words, the distillate is liable for tax.Managing the physical operation of the distillery is also significant as the delivery of good inwards, all of the chemical processes, health & safety and the cleaning regimes that go with them, as well as all of the records that accompany these activities, are a considerable requirement for a number of people.
Marketing and sales require considerable attention as these are the route to market for the finished products. As part of that focus, ensuring that the brand continues to resonate with customers and they are delighted with the quality of the product, are an essential aspect.
There are also numerous other areas that require attention, such as finance, IT, insurance and export laws. All of these activities must be balanced like spinning plates, in order to achieve the continued success of the distillery.