How to Make 1,000 Litres of Molasses Rum Wash the Easy Way!

How to Make 1,000 Litres of Molasses Rum Wash the Easy Way!

Dermott Dowling

The Australian sugar industry produces raw and refined sugar from sugarcane. Around 95 per cent of sugar produced in Australia is grown in Queensland and about five per cent in northern New South Wales, along 2,100 km of coastline between Mossman in far north Queensland and Grafton in northern New South Wales.

More that 80% of all sugar produced in Australia is exported as bulk raw sugar, making Australia the second largest raw sugar exporter in the world. In recent years, Asia has become a major focus with key export markets including South Korea, Indonesia, Japan and Malaysia which are our most important markets.

A natural byproduct of the sugar making process is molasses.  Molasses is a thick, dark syrup made during the sugar-making process. First, the sugar cane is crushed and the juice is extracted. The juice is then boiled to form sugar crystals and removed from the liquid. The thick, brown syrup left after removing the sugar from the juice is molasses. This process is repeated several times to produce a different type of molasses each time.  Molasses is a blend of sugar, cane solids, and some water.

Australia has a natural competitive advantage for craft Rum producers especially, those located in Queensland and northern New South Wales given our abundant supply of sugar and Molasses.  Here we will share a basic introduction and guide to make 1,000 litres of Rum Wash from Molasses.

Introduction

Crafting rum wash from molasses is the foundational step in rum production. This guide will walk you through the process of making 1,000 litres of high-quality rum wash, which will serve as the basis for your rum distillation.

Before you start, ensure you have the necessary ingredients and equipment:

Ingredients:

Molasses: 

The key ingredient for your rum wash. Choose high quality molasses, as it significantly influences the flavour of your final product.  At BeerCo.com.au we offer two types of high quality Molasses for Rum Distillers:

Individual batch certificates of analysis are available for the Bundaberg Refinery Molasses (Food Grade) and season production certificates are available for the Organic Molasses.  Both are available on the product pages.  Brix are typically 78-85% for the Organic Molasses and 76-81% for the Refinery Molasses.

Yeast:

Select a suitable yeast strain based on your desired rum style. Options available from BeerCo.com.au include Y1 Seltzer Pure Yeast,  DistilaMax® RM, DistilaMax® CN, DistilaMax® SR, or SafSpirit™ C-70.  Every yeast will have its own unique Congener profile and we recommend you refer to the product information on each page, the technical specifications and results from fermentation trials performed by the yeast manufacturer before choosing the yeast for the style of Rum you would like to produce.  Follow the instructions in terms of dosage and rehydration processes on the technical specifications listed on the products pages as well.

Rehydration Aids:

We recommend you follow the standard Rehydration Guide on your favourite Rum Yeast Product Data Sheet.  Here we share the Lallemand guide to rehydrate your Yeast.  Remember that Healthy and Happy Yeast = Delicious Rum Wash!

It is recommended to rehydrate the yeast before utilization. To rehydrate, add the yeast to a 10X volume of fresh water at 40°C (104°F), then stir and allow to stand for 15 minutes.

Pitching rates will depend on the process, but generally range between 10 and 50g/hl. Lower levels can be used if there is a conditioning stage before the fermentor. If added straight to the fermentor, temperature should be between 30°C to 35°C (86°F to 95°F).

Buffering Agents: 

Controlling the pH of your fermentation is also vital to ensuring a happy and healthy yeast and a clean fermentation with the desired esters as opposed to sulphur and other volatiles that unhealthy yeast will exhibit during a stress fermentation. If the pH is let to go too low you may also suffer from a stalled fermentation or stuck fermentation.  We recommend potassium bicarbonate or sodium bicarbonate or, at a rate of 1g per litre (per final volume) to control pH.  The buffering agents may be added at the start of fermentation or staggered depending on your fermentation process.

Yeast Nutrients and DAP: 

Molasses has more nutrients and trace minerals than refined sugar however it is still necessary and vital that you feed your yeast with the essential minerals and vitamins to aid their healthy development and insure you have a successful fermentation.  Options available to use include a combination or complete Yeast nutrient like DistilaVite® GN which contains a proprietary blend of inorganic nitrogen (diammonium phosphate), organic nitrogen (free amino nitrogen derived from inactivated yeast), and key vitamins and minerals including thiamine, niacin, folic acid, magnesium sulphate and calcium pantothenate. DistilaVite® GN also provides sterols and unsaturated fatty acids, which lend alcohol resistance to the yeast.  You will need to add diammonium phosphate at the recommended level of 0.5-0.7g/litre to help encourage a fast and vigorous fermentation.

Alternatively, some of our customers have achieved great results with a complete Yeast and Nutrient Buffering System like our N2 Agave Yeast Nutrient suitable for Agave Washes, Molasses Rum and Sugarcane and Juice based wasges and high fructose spirit washes e.g. grape andf fruit based brandy washes.  N2 Agave Yeast Nutrient ingredients contain: Diammonium Phosphate, Mineral Salts, Vitamins, Citric Acid, Inactive Dried Yeast.  It is a complete yeast nutrition and two stage buffering solution that is pitched at the beginning of your fermentation to feed the yeast and buffer the fermentation simultaneously.  For 6% ABV wash dose at 1.5g/L and for 12% ABV Wash dose at 3g/L.  Refer to the product page table for dosage guidance.

Equipment:

Fermentation Vessel: A large, cleaned, rinsed and sanitised ideally flat bottom or slightly curved fermenter with sufficient capacity to hold and ferment your 1,000 wash.  Temperature control is vital for a clean, consistent fermentation and yeast health so invest wisely in your fermentation vessels.  The ability to agitate your wash with an agitator or stirrer is also helpful if you are doing any high fructose or sucrose washes to keep the yeast suspended and active.  If you are not agitating the wash there is risk of the Yeast falling to the bottom of the fermenter with the heavy molasses and your fermentation stalling unexpectedly.

Hydrometer and Thermometer: To monitor and measure the wash temperature.  There are a number of floating measurement devices available now that can assist with measuring and reporting in real time your fermentation.  Some are listed below:

Refractometer: To measure sugar content (Brix) and monitor fermentation progress. Many professional brewers and distillers prefer to use a Refractometer to a Hydrometer for the speed and accuracy of measurement and ability to take small samples to test continuously during a fermentation.  Some options include:

pH Tester: Equally important to monitoring the sugar content (brix) of the fermentation is the pH and we recommend you invest in a quality pH tester from a reputable supplier.  We sell a number on our website and a popular choice for its dual functionality is listed below:

Multi-purpose measurement tools: We have seen the rise of some affordable and reliable measuring devices for the serious home brewer and distiller or small craft brewer and distiller that measure multiple key metrics from a small sample using a single device.  One example is listed below:

Stirring and Mixing Tools: For uniform distribution of ingredients.  Again we encourage you to consider seriously before purchasing fermenters and mashing and/or mixing tools all the various products you intend to produce in your distillery.  Upfront investment in capital that can heat, mix and insulate fermentation vessels will ensure you have maximum chance of creating clean, pure and consistent craft spirits in your Distillery.

The Fed-Batch Fermentation Process - Method #1 - Recommended Best Practice

Optimising Fermentation for Highest Ethanol Yield using Lallemand Biofuels & Distilled Spirits Guideline

Propagation

Step 1:

Fermentation (Fed Batch): For 1,000L, Fermentation time: 28-36 hours, Temperature: 32°-34°C

Step 2:

  • Add the rest of the water to your fermenter + 30% of the molasses (700 L of water and 75 L of Molasses)

Step 3:

  • After 10 hours, add 40% of the molasses (95 L of Molasses)

Step 4:

  • After 10 hours, add last 30% of the molasses (75 L of Molasses)

Distill

Step 5: Distillation

The Complete Batch Fermentation Process - Method #2

Yeast Rehydration

Step 1:

Lallemand Biofuels & Distilled Spirits recommends the rehydration of DistilaMax® RM, DistilaMax® CN, and DistilaMax® SR.  Refer to product pages for each specific yeast rehydration protocol.  Rehydrate your selected yeast strain as per the manufacturer's instructions.

  1. For rehydration, use a clean container. Do not use demineralized water.
  2. Rehydrate the yeast in clean water (the water should be 10 times the weight of the yeast and at a temperature of 32°C - 36°C).
  3. Suspend contents carefully by gently stirring and then wait for 15 - 20 minutes maximum (minimum 10 minutes) before moving onto the next step.
  4. Add this preparation to the wash. If there is a temperature difference of more than 8°C between the wash to be inoculated and the rehydration solution, add some wash slowly into the rehydration solution to reduce the temperature difference.

Molasses Wash Preparation

Step 2:

Mix the full contents of 250 litres (approx. 350Kg) molasses with 750 litres of water.  Measure the Brix (starting gravity).  Buffer the pH with 1g/L of potassium bicarbonate and check and maintain a pH above 3.5 at all times during the fermentation and bring it up as necessary.

Add the rehydrated yeast to the wash and gently stir for even distribution. Add all  of your Yeast Nutrients and DAP at the start of your wash

Step 3:

Cover the vessel and maintain a warm temperature between 25-35°C during the initial fermentation period. Allow this stage to proceed for 12-24 hours.  Note: the lower the wash fermentation temperature the slower the fermentation and the less esters the yeast will produce. Likewise the warmer the fermentation the faster the fermentation and the more esters the yeast will produce.  Most professional distillers yeasts are designed to run at the upper range of their optimal temperature range.  Please always refer to our product pages and technical data sheets for this information.  We would recommend that you run around 32°C if you can control the temperature effectively.

Step 4:

After the initial 24 hours, measure the Brix (gravity) and pH, degas as necessary and Buffer the pH back to the ideal fermentation range for your Yeast (refer to product pages and technical data sheets).  You will note many professional Rum Distillers yeast are highly pH tolerant and you will see pH drop naturally as fermentation progresses.  Use potassium bicarbonate to bring the pH up as necessary.  Try not to overdose your pH buffering aids as they will have an impact on flavour of the wash in high dosages.

    Step 5:

    After an additional 24 hours, (48 hours total) measure the Brix (gravity) and pH, degas and oxygenate as necessary and Buffer the pH back into the ideal fermentation range for your Yeast (refer to product pages and technical data sheets).

      Distill

      Step 6: Distillation

      Conclusion

      Following this guide will allow your craft distillery to produce 1,000 litres of rum wash from molasses. Remember that crafting exceptional rum involves patience and experimentation. The quality of your ingredients, yeast selection, and attention to detail throughout the process will influence the unique flavours and characteristics of your final rum.

      As you proceed with fermentation, make notes and adjustments to refine your process for future batches. Continuously learning and improving your techniques will lead to the creation of exceptional craft rum.  In future blogs we will discuss in greater detail the distillation techniques and use of Dunder, Muck and other interesting ways to really make your Rum Shine!  Cheers #DistilSafely and please do not hesitate to reach out to us at service@beerco.com.au anytime to discuss your brewing and distilling needs.