Hydrometer Instructions

People have asked if I would provide some simple instructions on how I measure the Sugar content in Rum. Below are listed the few simple steps needed to make an estimated calculation.


You will need the following:

  1. The Rum you want to measure. With the equipment I use, this requires at least 21cl of rum.
  2. A Hydrometer/Alcoholmeter capable of measuring with high precision. I use 6 different Alcoholmeters, each covering a range of 10% with a precision of 0.1% (e.g. 0-10%, 10-20%, 20-30% .... ).
  3. A Beaker in which the rum is measured. I use a 250mL beaker with a diameter of 3cm (That's why I need at least 21cl to do a measurement).
  4. A Thermometer to measure the temperature of the Rum.
  5. My conversion table
  6. Temperature correction table if Rum is not 20 degree Celsius


The steps are as follows:


1. Pour 21cl of rum into the beaker. Measure the temperature to make sure it's 20 degree Celsius (if not, you have two options, cool/heat the rum to 20 degree Celsius or make a note of the temperature and use a correction table later).

2. Using the Alcoholmeter, measure the % abv. level of the rum. Make a note of the measurement. If the measurement is not done at 20 degree Celsius, use the temperature correction table to find the % abv value at 20 degree Celsius.


3. Read the % abv. listed on the label. Make a note of the value. According to EU regulations, the % abv listed on the label must be within 0,3% accuracy of the rums actual % abv.


4. Use my table and the two values found in step 2 and 3 above (example values are 35.3% and 40%) to find the sugar level in gram/Liter. In this example, I measured 35.3% so the sugar in g/L ends up somewhere between 15 and 19 g/L. In this example I would say 18g/L.



If you don't have a temperature correction table for your Alcoholmeter (In case you measure the % abv at a temperature other then the one your Alcoholmeter is calibrated at (normally 20 degree Celsius)), use a search engine and look for "Correction Table for an Alcoholometer Calibrated at 20oC"







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