Beer Brewing Hydrometers - Establish ABV % (alcohol by volume) using a Hydrometer

A hydrometer is commonly used in the beer making process to check specific gravity of the liquid which is about to be fermented. This specific gravity reading is important as it then can then be used to calculate the amount of sugar content in the liquid.

The general principle is:

• The more sugar in the liquid, the higher the reading.
• The more alcohol in the liquid (after fermenting), the lower the reading.

Which hydrometers do I use?

There are two common hydrometers we sell for brewing purposes. The first hydrometer is the JD1011 density hydrometer which is calibrated at 20.0°C and the second is the HSG1011 specific gravity hydrometer which is calibrated at 15.6°C. Both hydrometers will serve the same purpose, however, selecting the correct model will depend on your specific process.

Details on both key hydrometer models can be found by following the links below:

1. JD1011 - Density Hydrometer with ranges between 1.000-1.100: https://www.labdirect.com.au/density-hydrometer-1-...
2. HSG1011 - Specific Gravity Hydrometer with ranges between 1.000-1.100: https://www.labdirect.com.au/specific-gravity-hydr...
3. HJ40 - Hydrometer Jar: https://www.labdirect.com.au/hydrometer-jar-40od-3...

You can easily establish the approximate ABV % of your brew by using one of our hydrometers. 

To calculate the approximate ABV % of your brew, simply subtract FG (final gravity) from OG (original gravity) and multiplying by 131.25. 

ABV = (OG-FG) x 131.25 

Example ABV = (1.040-1.010) x 131.25 

• OG stands for Original Gravity – This refers to the starting gravity of the wort before fermentation begins. 
• FG stands for Final Gravity – This refers to the finishing gravity once fermentation is complete. This value also allows you to determine whether fermentation has completed.

Quick points

• Most hydrometers used by home brewers are scaled for specific gravity readings between the ranges of 1.000 (for water) to 1.100 (for high gravity barley wines).
• An average beer generally has a starting gravity between 1.040 and 1.050 and a final gravity around 1.010.
• Both hydrometers are supplied with certificates of conformity for ATO purposes.
• Hydrometers placed water at 20°C should read 1.000.