Rum Recipe

Prepare must

Sanitize all fermentation equipment (fermenter, airlock, spoons) with a no-rinse sanitizer. Warm 5 liters of molasses slightly so it flows easily (40–50°C). In a large sanitized fermenter, dissolve the molasses into 10 liters of warm water, stirring until homogenous. Add the optional 500 g granulated sugar if you want higher starting gravity for a stronger wash. Top with additional cool water to reach a total volume of 20 liters. Aim for a starting specific gravity between 1.070 and 1.090 (use a hydrometer).

Adjust nutrients and pH

Stir in 5 tsp yeast nutrient. Check pH; if it is above 5.5, add up to 2 tsp citric acid gradually to bring pH to 4.0–5.0 (ideal ~4.5). Cool the must to pitching temperature (24–30°C).

Pitch yeast

Rehydrate or prepare 20 g of rum-specific yeast according to the manufacturer's instructions (or sprinkle if using dry yeast). Aerate the must well (pouring between sanitized containers, or use an aeration stone briefly) so yeast has oxygen for the first 24 hours. Seal fermenter with an airlock.

Primary fermentation

Allow fermentation to proceed at 22–30°C for 5–10 days. Active bubbling should occur; monitor gravity. Once bubbling slows and gravity stabilizes between 1.000 and 0.995 (or close to terminal gravity), fermentation is complete. This wash will contain alcohol by volume in the 8–12% range depending on starting gravity.

Clarify and prepare for distillation

Rack (siphon) the wash off heavy lees into a sanitized still, leaving sediment behind. If desired, cold-crash the wash or use fining agents to clarify before distilling to reduce solids and foaming.

First run (stripping run)

Fill the still with the clarified wash to the recommended fill level. Heat slowly and perform a stripping run to collect the low-strength distillate (rough spirit) primarily to concentrate alcohol. Collect distillate until boiler alcohol by volume (ABV) of output falls below ~20% ABV. This run yields a concentrated spirit that will be re-distilled for spirit-quality rum.

Spirit run (cuts and heads/tails)

Clean and refill the still with the stripped low wines (or dilute if necessary to recommended charge ABV). Slowly heat and make cuts carefully: discard the foreshots/heads (first 50–200 ml per 20 L wash, or until strong solvent/acetone smells subside), collect the heart (the desirable rum fraction) at a steady ABV — typically collect hearts while ABV is between ~80% down to 60% depending on your still and preference — and separate tails when heavy, oily smells or rapidly falling ABV indicate fusel oils. Record volumes and ABV for dilution calculations later.

Optional charcoal filtration

If a cleaner, lighter rum is desired, filter the collected hearts through activated charcoal. Pour the spirit slowly through a filter packed with 200 g activated charcoal into a sanitized container, then re-proof with distilled water as needed.

Oak aging

Transfer the cleaned hearts into an oak barrel or add 200 g medium-toast oak chips in a sanitized container. Age for a minimum of 3 months for noticeable oak character; 6–12 months or longer for more complexity. Store in a cool, dark place and taste periodically.

Proofing and smoothing

When aging is complete or you are ready to bottle, measure the spirit ABV and dilute with distilled water to target bottling strength (typically 40% ABV). Optionally add up to 50 g sugar (simple syrup) or a small amount of caramel color for sweetness and rounding — dissolve sugar in a small amount of water and add gradually to taste. Chill and allow the spirit to marry for several days before final bottling.

Bottling

Filter the final rum to remove any particulates (optional). Sanitize bottles and caps. Fill bottles, seal, label with date and style, and store upright in a cool place.