Each homebrew will be different so there’s no standard answer to how much alcohol is in homebrew.
ABV stands for Alcohol by Volume. This represents how much of any liquid is alcohol. If a beer is 4% ABV that means 4% of that beverage is alcohol.
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How to calculate ABV?
First you need to calculate the original gravity (OG). This is the amount of sugar in the wort before fermentation.
Second you need to calculate the final gravity (FG). This is the measurement of sugar after fermentation.
Finally, you need to take the OG and FG and place them into a ABV calculator like the one below.
In this example the OG is 1.05 and the FG is 1.01. With those numbers you can see the ABV of the homebrew is 5.25%. Find the online calculator here: https://www.brewersfriend.com/abv-calculator/
How to calculate the OG and FG?
There are 2 common tools homebrewers can use to calculate these numbers.
- Hydrometer
- Refractometer
The hydrometer is a tool used to calculate the ABV. When placed inside a cylinder of homebrew it will float. Based on the contents of the liquid it will float at different levels. More sugar and it floats higher, less sugar and it floats lower.
The Refractometer measures how light travels through a liquid. Depending on the sugar level the light will travel at different angles. The refractometer can be used to calculate this.
Why are the OG and FG different?
The OG and FG are different because of fermentation. This is the process of converting sugar into alcohol.
Because these tools are measuring sugar, you will have a lower reading after fermentation because there is less sugar.
If you don’t have a lower number after fermentation that means either your tools don’t work or fermentation didn’t happen. Hopefully it’s not the latter!
That’s it!
That is how you figure out how much alcohol is in homebrew.
Now if you’re ready to brew some beer check this out: