Alcohol Measuring Hydrometer

Hydrometer Calibration (Optional)
For greater accuracy, you can calibrate your hydrometer before each use to ensure accurate readings. Immerse the hydrometer in filtered water at 20°C. It should read 1,000. If this is not the case, adjust the hydrometer according to the manufacturer's instructions or make a note of the difference to correct your measurements.

Sample Preparation
For reasons of hygiene and convenience, it is best to fill a test tube with the liquid (sample) to be analyzed. The liquid should not be returned to the carboy to avoid contamination. If you wish to return the liquid, sanitize the hydrometer and any equipment you are going to use.

Immersion of the Hydrometer in the Sample
The hydrometer is a fragile glass tool that doesn't take kindly to shocks and sudden changes in temperature, so place it gently in the fermented liquid. Make sure it floats freely without touching the sides of the container. For the most accurate results, avoid creating bubbles when inserting the hydrometer. You can rotate the hydrometer on itself with a slight twist of fingers to remove any bubbles.

Taking the Reading
Allow the hydrometer to stabilize, then take a reading from the surface of the liquid. This reading, known as the specific gravity, is crucial for calculating the alcohol content. The reading taken before fermentation is called the initial specific gravity, while the reading taken at the end of fermentation is called the final specific gravity.

Calculating the Alcohol Content
To estimate the alcohol content, you'll need two specific gravity measurements: one before fermentation (initial gravity) and one after fermentation (final gravity). The difference between these two values is needed to calculate the approximate alcohol content using the following formula:

• Alcohol (%) = (Initial density – Final density) x 131.25
• So, if your initial density was 1,050 and your final density was 1,000, your beverage contains around 6.5% alcohol.