Calculating the alcohol content of a wine that you made is always fun. While amateur wine makers don’t need to report this value to anyone it’s just neat to know how much alcohol you’ve produced.

A winery lab setup for determining alcohol content.

Winery determining alcohol content through distilling.

 

Use Wine Equations and Calculators Only

There are many formulas out there for calculating the percent alcohol of wine and beer. You may have noticed that they’re not the same. Largely this is because the relationship between the specific gravity and the amount of alcohol produced is not linear.

What this means is that specific gravity and alcohol content have a complex relationship that is not easily represented with a simple equation. Non-linear equations can be pretty nasty to deal with.

To get around these nasty but accurate equations simpler equations have been developed but they are only relevant for a small range of alcohol content. Wine, typically has an alcohol content of around 11-15% while beer is usually around 5-6%. Because of this they each have their own alcohol content equation based on these different ranges of alcohol.

In short be sure that you’re using an equation specific to wine making. A beer equation can lead to incorrect results.

 

The Wine Alcohol Content Calculator

The simplest way to calculate your alcohol content is with a calculator. You’ll need to know your starting or original specific gravity that you took before fermentation began. Also, you’ll need the final specific gravity taken once your wine has finished fermenting and is stable. Just plug in both values and press calculate.

 

Original Specific Gravity:
Final Specific Gravity:
% Alcohol by Volume:

 

This is about as accurate as you can get with the equipment and methods available to amateur wine makers. Wineries use distilling equipment as shown above to get a more exact alcohol content.

To ensure that you get as accurate a result as you can you need to take accurate specific gravity readings. Also, be sure to do your temperature corrections for the greatest accuracy.

Check out this article and calculator for correcting your specific gravity readings for temperature.

 

The Equation for Calculating Alcohol Content

For those of you who’d like to know the equation behind the calculator here it is.

The simple equation for calculating wine alcohol content. %ABV = [Original SG - Final SG] / 7.36 * 1000

It’s simple enough to use in a spreadsheet or calculate by hand.┬áNote, that this equation yields wine alcohol content as a percentage of alcohol by volume. There are other equations for alcohol by weight, however, wine alcohol content by volume is the most prevalent way to report alcohol levels.

Photograph by: Robert Pitkin

  • Hi Bill, this is definitely on my radar. I apologize for the inconvenience. I’m not a javascript programmer and was only able to cobble that calculator together. Fixing it has been a challenge. I will hopefully have it back up soon.

    -Matt

  • Craig Webster

    The formula worked when I entered into the spreadsheet I have been using as a diary to log the batches. Craig