How to Test the ABV in Wine

Test the ABV in wine using a hydrometer.

When making your own wine you need to test the ABV to find out how much alcohol it contains. ABV, Alcohol by Volume, is the standard means of illustrating how much alcohol wine contains expressed as a percentage. To test the ABV of wine, you need to measure the specific gravity of the wine before it is fermented as well as after. Specific gravity is a measure of the density of liquids relative to the density of water.

Things You'll Need

• Hydrometer
• Thermometer
• Tall, narrow clear flask

Instructions

1. Place a sample of the unfermented wine into the flask then place the hydrometer into the flask. Make sure the hydrometer is floating freely in the liquid.

2. Read the measurement against the scale of the hydrometer where it sits at the top of the liquid. This figure is the original gravity. Take careful note of this figure.

3. Measure the temperature of the liquid and take note of this figure. The temperature is important as hydrometers are calibrated to record at a standard temperature, normally 60 degrees Fahrenheit. The gravity readings may therefore need to be adjusted according to a scale normally supplied with each hydrometer before making your final calculations.

4. Add the yeast to your wine must (unfermented wine) and allow it to ferment according to the recipe you are following. When fermentation has stopped, you can take the next reading, which will allow you to calculate the ABV.

5. Place a sample of the fermented wine into the flask with the hydrometer and take note of the final gravity figure. Check the temperature and take down this figure.

6. Adjust your figures for original and final gravity to take account of any deviation from the standard temperature of 60 degrees Fahrenheit. Instructions will normally be enclosed with your hydrometer but you can also use the online tool through the link in the Resources section below.

7. Subtract the adjusted final gravity from the original gravity then multiply the result by 131 to obtain a figure for percentage ABV. For example, a final gravity of 1.005 subtracted from the original gravity of 1.070 gives 0.065. Multiplied by 131, this gives an ABV of 8.5 percent.

Tips & Warnings

• If you fail to adjust your readings for temperature variations it is likely you will get an inaccurate figure for the ABV of your wine.

References

• Brew: Measuring Alcohol
• Maypole Brewery: ABV Explained

Resources

• Brewers Friend: Hydrometer Temperature Adjustment Calculator