This dilution calculator tells you how much water to add to bring a spirit down from its current strength to a target strength, such as 40% ABV for bottling. It uses the standard dilution formula: final volume = current volume × current ABV ÷ target ABV, and water to add = final volume − current volume. Measure the current strength with an alcometer first.
Worked example
You have 1 litre of spirit at 40% and want it at 30%. 1 × 40 ÷ 30 = 1.333 L, so add about 333 mL of water. Or take 4 L at 60% down to 40%: 4 × 60 ÷ 40 = 6 L, so add 2 L of water and you have enough for about eight 700 mL bottles.
Tips for diluting spirit
- Use clean filtered, distilled or demineralised water. Hard tap water can turn spirit cloudy.
- Add the water slowly and stir, then let it rest for a day before checking the strength again.
- Re-check with an alcometer at about 20°C and top up with a little more water if needed.
- Dilute before adding an essence unless the essence instructions say otherwise.
FAQ
Why is my final volume a little less than the calculator says?
Alcohol and water contract slightly when mixed, so the final volume comes out a little smaller and the strength a touch lower. The difference is small; check with an alcometer and adjust.
Why does my spirit go cloudy when I add water?
Usually minerals in the water or oils from the heads and tails of the run. Use filtered or distilled water, and carbon filter the spirit first.
What strength should I bottle at?
Most spirits are bottled at 37–40% ABV. Liqueurs are usually lower, around 20–30%; follow your essence's instructions.
Gear and guides: alcometers and testing gear, carbon filters, carbon filtering guide, bottles. More tools: ABV calculator, essence calculator, priming sugar calculator.
