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Winemaking Article
Quick Reference Guide
Estimating a Wine’s ABV and Residual Sugar in 3 Easy Steps
Before you start, you will need the starting SG (specific gravity measurement taken with a hydrometer immediately before fermentation), and the final SG taken after fermentation. See Frequently Asked Questions if needed.
STEP 1:
Calculate the ABV (Alcohol By Volume percent) in the wine using:
(SGstart – SGfinal) x 132 = ABV
If you needed only the ABV for your wine, you are done. If you also want to find its residual sugar, continue to the next step.
STEP 2:
Using the final SG measurement and the ABV from the previous step, enter the plot of Figure 1 below to determine the combined extract/residual sugar level:
- Find the final SG on the vertical axis.
- Find the ABV on the horizontal axis (labeled "Volume% Alcohol") and move straight up until it crosses the line of the final SG. Note that location.
- Note the diagonal line that crosses that location (or the two diagonal lines that are immediately above and below that location). Find the percentage in the legend that corresponds to the diagonal line (or interpolate the percentage that lies between the two diagonal lines). This is the combined extract/residual sugar level in the wine; that is, it includes non-sugar solids.
Don’t forget to proceed to Step 3!
Figure 1: Chart for determining combined extract/residual sugar level
STEP 3:
Choose the correct number from Figure 2 below (amount of extract), then subtract that from the result of Step 2 to obtain the wine’s Residual Sugar percent.
Figure 2: Amount of extract (non-sugar solids) in wines
| Type of wine: | Amount of extract: |
| Red grape | 3 |
| White grape or other fruit | 2.2 |
| Herb or flower (no juice added) | 1.5 |
That's It!
You now have your wine’s alcohol and residual sugar content. Keep in mind that these numbers are only estimates; many factors may have an affect on the actual amounts present.
Frequently Asked Questions:
What is ABV and why should I measure it?
ABV is short for Alcohol By Volume, which is the percentage of alcohol in a beverage. You want a dry wine to contain at least 11% alcohol to keep it from spoiling before you drink it, but not too much more than that or it will taste “hot”. However, in sweeter wines a higher ABV may be useful to balance the sweetness; in fact, dessert wines usually contain over 14% alcohol.
What is residual sugar and why should I measure it?
Residual sugar is the leftover sugar present after fermentation. Its presence can be a problem if it indicates that not enough sugar has been converted into alcohol, or if you are concerned about fermentation restarting in the bottle, or if you don’t like your wine sweet.
Also, some wine competitions require that you enter your wine in an appropriate category based on its residual sugar content. Please note that any sugar added after fermentation contributes to a wine’s residual sugar and should also be considered when choosing the appropriate category.
What if I don’t have specific gravity readings for my wine?
No problem, as long as you have the starting and ending Brix. Simply look at your hydrometer, find the starting Brix on it, then follow horizontally until you find the corresponding SG for that Brix. Repeat for the ending Brix.
Will this "Guide for Estimating ABV and Residual Sugar in 3 Easy Steps" work for any wine?
Yes, as long as you don’t make sugar additions or fortify during fermentation.
However, if you added your sugar in stages during fermentation, and you are an experienced enough winemaker to be able to estimate what the starting SG would have been if the sugar were added all at once, then you can still use this guide.
What if I sweeten or fortify my wine before bottling?
For accurate results, use an SG taken before sweetening as your final SG. Of course you’ll then have to update the residual sugar amount with the new sugar.
Likewise if you fortify your wine. For your final SG, use a reading taken before the spirit is added to the wine, then update the ABV with the additional alcohol content.
What is “extract” and why do we need to subtract it?
Extract consists of various compounds in wine including acids, tannins, glycerol and the pigment that gives the wine its color. We also call it “non-sugar solids”, because it’s not sugar but it still registers on your hydrometer, thus making it look like there is more sugar present than there really is. You have to account for the extract to get an accurate estimate of residual sugar present.
May I see an example of this "Guide for Estimating ABV and Residual Sugar in 3 Easy Steps" being used?
FIRST EXAMPLE:
A Riesling started out with an SG of 1.088. At bottling its SG was .992.
In Step 1, we calculate the amount of alcohol in the wine:
(1.088 – .992) x 132 = 12.7% ABV
In Step 2, we look at the chart.
First, we look for our final SG of .992 on the vertical axis. It’s a little above the .990 line.
Then, we use the 12.7 ABV from Step 1 and find it on the horizontal axis. It’s about halfway between 12 and 13, but a little closer to the 13.
We need to move straight up to find where the 12.7 crosses the .992 SG (hint: lay a ruler vertically to help you go straight up). Where they cross is just above the diagonal line that is labeled 2%, so our combined extract/sugar is a little over 2%.
In Step 3, we subtract the extract (non-sugar solids) from the result of Step 2. Since this is a white wine, we need to subtract 2.2 from “a little over 2”. It looks like this wine has about zero residual sugar, which is why it tastes very dry.
SECOND EXAMPLE:
We have a Leon Millot whose starting SG was adjusted with sugar syrup to be 1.100, in an attempt to get a dry wine with an alcohol level of 14% ABV. It's final SG was 1.000.
In Step 1, we calculate the ABV to be:
(1.100 – 1.000) x 132 = 13.2%, which is a little lower than planned.
In Step 2, we use the chart:
First, we look for the final SG of 1.000 on the vertical axis.
Then, we use the 13.2% ABV from step 1 and find that on the horizontal axis. It's a little to the right of the 13.
We move straight up to find where the 13.2 crosses the 1.000. Where they cross is about halfway between the diagonal lines labeled 4% and 5%, so the combined extract/residual sugar is about 4.5%.
In Step 3, we subtract the extract (non-sugar solids) from the result of Step 2. Since this is a red grape wine, we subtract 3 from the 4.5, and obtain a residual sugar level of about 1.5%.
The presence of this sugar explains why the ABV was lower than the planned 14%, and why the wine tastes somewhat sweet.
For more information, see the research that this guide is based on at Determining ABV and Residual Sugar.