Our Craft

As small and honest rum producers we want to be open about our production process. The rum spirits category is a category where the rules and habits differ a lot per region and brand. Because of this, rum can be very diverse. This diversity also has a downside, as a customer you don’t always know what you are buying. We would like to be one of the producers who gives all the pieces of information about our rum production so you know what you buy.

“At Rummieclub we are rum makers, this is our craft. We do everything ourselves, from fermentation until botteling and labelling. This gives us full control over all aspects of our rum production.”

1. Ingredients

Like all rum production we start with sugar cane; in our case with molasses. Molasses is the dark and sticky stuff that’s left after they extracted sugar cane crystals from the sugar cane. We use an organic molasses with still around 60% sugar from Paraguay. As sugarcane needs at least 25 degrees we can not get the molasses close to our home. We experimented with lots of different molasses from different origins and this was our clear winner in taste and yield. Every 3 months we receive two IBC’s of 800 liter of this wonderful stuff and we use 100 liter per 500 liter fermentation. 

2. Fermentation

Fermentation is the process where sugars are converted into alcohol and CO2. The only thing we add to our fermentation is molasses, water (filtered by the dutch dunes) and yeast. Our fermentation  process is different for all our rums. Most of the fermentations are around 6-8 days and are not temperature controlled. The fermentation we run in our Istill is a bit shorter (4 to 5 days) and is temperature controlled between 25°C and 28°C degrees, this usually means we cool at the beginning of the fermentation as the fermentation makes a lot of energy/warmth.  We also do some fermentations around 10 to 14 days where we try to increase the acidity as the combination of acids with alcohol creates interesting flavour molecules called esters. We also sometimes try to make our fermentation more acid by using the leftovers from our former distillation, this leftovers are called backset or dunder. 

We have experimented with a lot of different commercial yeasts. For our aged rum we use one of these that gave us the most fruity and intense flavour we were looking for. For some of our white un-aged rum we are trying to cultivate our own yeast from raspberries. During our search for the desired flavor, wild yeast gave us very good results. It also presents us with great challenges with regards to consistency. Yeast tends to change and adopt to its environment. In our fermentation tanks the environment is like heaven for yeast and it will lose those properties that create the wanted flavors. This can be solved with a yeast lab and sub-zero storage that deep freezes our samples. We don’t have that, which means flavor can vary a little bit. Some of our fermentations stay open and the commercial yeast gets to work together with some wild yeast and bacteria. There are lots of factors like the weather which plays a role in the fermentation and therefore every fermentation is unique. 

Fermentation is the process where sugars are converted into alcohol and CO2. The only thing we add to our fermentation is molasses, water (filtered by the dutch dunes) and yeast. Our fermentation process is different for all our rums. Most of the fermentations are around 6-8 days and are not temperature controlled. The fermentation we run in our Istill is a bit shorter (4 to 5 days) and is temperature controlled between 25°C and 28°C degrees, this usually means we cool at the beginning of the fermentation as the fermentation makes a lot of energy/warmth. We also do some fermentations around 10 to 14 days where we try to increase the acidity as the combination of acids with alcohol creates interesting flavour molecules called esters. We also sometimes try to make our fermentation more acid by using the leftovers from our former distillation, this leftovers are called backset or dunder. We have experimented with a lot of different commercial yeasts. For our aged rum we use one of these that gave us the most fruity and intense flavour we were looking for. For some of our white un-aged rum we are trying to cultivate our own yeast from raspberries. During our search for the desired flavor, wild yeast gave us very good results. It also presents us with great challenges with regards to consistency. Yeast tends to change and adopt to its environment. In our fermentation tanks the environment is like heaven for yeast and it will lose those properties that create the wanted flavors. This can be solved with a yeast lab and sub-zero storage that deep freezes our samples. We don’t have that, which means flavor can vary a little bit. Some of our fermentations stay open and the commercial yeast gets to work together with some wild yeast and bacteria. There are lots of factors like the weather which plays a role in the fermentation and therefore every fermentation is unique. 

" Fermentation is where flavors are created. We think this is the most important part of rum making. This is also where we spend most time on product development​ "

3. Distilling

At the end of the fermentation period the wash is around 8% alcohol and is pumped in to our still: the Istill 500, a 500 liter still. Istill is a Dutch company from Woerden that makes a lot of stills, mostly for craft distilleries. They are specialized in automation and robotization. That doesn’t mean you don’t have to do anything yourself, but it does mean we have a lot of control to make all the choices we want and can make a lot of different rums. It has a stainless steal boiler with a direct heater in the boiler. We use copper waffles to extract some undesired compounds. On top of the boiler there is a packed column with a robot that opens and closes this column as we want it. It has a lot of temperature probes and different valves for the heads, hearts and tails cuts, which we make based on temperature and taste. We chose this still because it’s very energy efficient and gives us the control and options we were looking for.

4. Ageing

After the distillation the rum is somewhere between 75 and 88 percent ABV depending on the wash and the distillation program. After this it will either rest in stainless steel tanks for a month or two or go into a ex-bourbon cask, most of the time at 60% abv. We have ex-bourbon casks in 100 and 200 liter from the Jim Beam and the Jack Daniels distillery. It takes us around 5 fermentation batches to fill up one cask of 200 liter. To bring our rum to cask proof or the desired ABV of a bottle we use an extra filtration of our water with reverse osmosis. 

5. Bottling

After the aging or resting time the rum will be bottled and labeled by hand in our distillery. As our aged rums are still in the barrel we now have two editions of Rummieclub rum for sale: Colourful White (40% abv) and Overproof (58%).  Every edition of Rummieclub rum has a artwork on the frontlabel which is made by a different local (graffiti) artist. The Colourful White artwork is made by Mick La Rock and represents her view on the bubbles and fumes of distillation. She also made this as a mural in our distillery with graffiti. The Overproof artwork is made by Munir the Vries and represents animals getting drunk from overripe fruits.