Chaptalisation

Chaptalization is the process of adding sugar to unfermented grape must in order to increase the alcohol content after fermentation. The technique is named after its developer, the French chemist Jean-Antoine-Claude Chaptal. This process is not intended to make the wine sweeter, but rather to provide more sugar for the yeast to ferment into alcohol.

Chaptalization has generated controversy and discontent in the French wine industry due to advantages that the process is perceived to give producers in poor-climate areas. In response to violent demonstrations by protesters in 1907, the French government began regulating the amount of sugar that can be added to wine.

Chaptalization is sometimes referred to as enrichment, for example in the European Union wine regulations specifying the legality of the practice within EU.

The legality of chaptalization varies by country, region, and even wine type. In general, it is legal in regions that produce grapes with low sugar content. Chaptalization is prohibited in Argentina, Australia, California, Italy, and South Africa. Germany prohibits the practice for making Prädikatswein. It is generally permitted in regions where grapes tend to have low sugar content, including Northern regions of France, Germany, and the United States.

The technique of adding sugar to grape must has been part of the process of winemaking since the Romans added honey as a sweetening agent. While not realizing the chemical components, Roman winemakers were able to identify the benefits of added sense of body or mouthfeel.

While the process has long been associated with French wine, the first recorded mention of adding sugar to must in French literature was the 1765 edition of L'Encyclopedie, which advocated the use of sugar for sweetening wine over the previously accepted practice of using lead acetate. In 1777, the French chemist Pierre Macquer discovered that the actual chemical benefit of adding sugar to must was an increase in alcohol to balance the high acidity of underripe grapes rather than any perceived increase in sweetness. In 1801, while in the services of Napoleon, Jean-Antoine-Claude Chaptal began advocating the technique as a means of strengthening and preserving wine.

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