What Does it Mean to Chaptalize Wine?

Chaptalizing is the act of adding sugar to a grape must in order to increase the alcohol content of the finished wine. Since yeast consumes sugars to produce alcohol, if you add sugar to grape juice before or during fermentation the yeast will have more sugar to convert thus yielding higher alcohol levels.

This process is widely regulated in commercial wine making depending upon where in the world you are located. The US has federal regulations (available here) and some states enact their own regulations to go on top of the federal ones.

An Interesting History of Chaptilizing Wine

1907 Protest in France over Chaptalizing Wine

News coverage of the 1907 protest.

Chaptalization was widely done in France for many years until 1907 when the industry began a protest. At the height of the protest 900,000 people rallied against the practice of adding sugar to grapes to make higher alcohol wines.

The cause of the unrest was a flood of cheap wines that had hit the market and driven the price of all wines down. These cheap wines were made from sub-par fruit that was doctored with additional sugar to produce a wine with higher alcohol content.

To keep the protesters in check the French Army was called out (this never turns out well in any country). Mayhem ensued and five people wound up dead. The very next day the protest continued with a local government building being burned to the gruond.

As a result of the protest the French government put into place restrictions on how much the final alcohol content may be influence as well as when it is even legal to chaptalize wine. In France the final alcohol content cannot be raised more than 2% by volume. The US has similar standards, however, the US also limits the maximum percent alcohol that the final wine can be.

The Process of Chaptilizing Wine

Chaptalizing wine is the process of increasing the sugar content of the must in order to produce a higher alcohol content wine.Chaptalizing wine is simple. You merely add sugar to your must prior to starting fermentation. It is easiest to add it before fermentation begins so that you can get an accurate specific gravity reading. However, you can also add the sugar during fermentation but you’ll have to do your own calculations to determine the final alcohol content.

Sugar may be added in the form of granular sugar or grape juice concentrate for most commercial wineries. Amateur wine makers, of course, are free to use whatever they like including honey, powdered fructose, and dried fruit.

With your sweetener of choice in hand you merely mix it in completely, take your chemistry readings, and then inoculate your yeast to begin fermentation.

How Much Sugar Do I Add?

The quantity of sugar you add is a more complex subject. As with most decisions you make regarding your wine it is best to begin with the end in mind. How much alcohol do you want your finished wine to have?

Here’s a simple relationship to help you figure it out:

1.5 oz of sugar will raise one gallon of wine by 1 Brix.

Let’s work through a quick example. Say I have some Pinot Noir grapes and I know that I want my finished wine to be at least 14% alcohol. In order to have 14% alcohol my grapes need to have a sugar content of at least 23.5 brix.

I have enough grapes on hand to produce 100 gallons of must. Unfortunately it’s been a tough year here at the vineyard and the sugar level is only 21 Brix which will only yield 12.2% alcohol. Thus I need to raise 100 gallons of must 2.5 Brix.

Going back to the relationship above is my calculated sugar addition:

100 gallons x 2.5 Brix x 1.5 oz sugar = 375 oz of sugar or 23.4 lbs

Things to Keep in Mind

Remember that each yeast strain has a maximum amount of alcohol that it can tolerate. You need to make sure that the yeast you’ve chosen can handle the final alcohol level that you’re intending to produce. In our example above the alcohol levels were modest enough that most most commercially available wine making yeasts will be able to handle this.

It is entirely possible, however, to push your wine into the 16-18% ABV range if you so choose. At this point yeast selection becomes imperative. Check out How to Pick a Wine Making Yeast for more information on the complete process.

Chaptalizing your wine won’t make the finished wine any sweeter. To finish your wine sweet you’ll need to either stop your fermentation (difficult for the home wine maker) or back sweeten your wine after fermentation ends. The latter is the preferred method at the amateur level.

Photograph of hydrometer by: Mark Smith

French journal cover is in the public domain and is available here.