Information on Making Wine

Vitis vinifera is the species of grape most commonly used to make wine.

The science of making wine is referred to as enology. The three categories of wine are table wines, fortified wines and sparkling wines.

Types of Wines

Table wines ferment naturally and include rose, red and white wines. Sparkling wines are created in a similar way to table wines but they include a step for adding carbonation. Fortified wines require extra steps to give them more alcohol. This involves adding a spirit or alcohol solution that increases the alcohol level up to 20 percent.

Picking Grapes

Grapes are cleaned to remove bugs and leaves and then are placed into a machine which presses them to extract the juice. Grapes must be picked at the correct time of day so that the sugars and acids are in the right concentration. In warm regions this often means picking at night so that the grapes are cool when they come in to be processed. The skin of the grape is left on when making red wine, giving it the red color.

Fermentation

Fermentation is a chemical reaction in which sugar is turned into an alcoholic solution. Because high sugar content is required for fermentation, a type of grape that is rich in sugar is used for many wines produced across the world. The species Vitis vinifera, that today has almost 4,000 varieties, is perfect for winemaking. Yeast is added to the grape juice and the juice is placed in airtight vats to prevent oxidation and bacterial growth. The fermentation process can take up to 30 days.

References

• Environmental Studies: Whitman College: The Process of Winemaking
• Wine Intro: Red Winemaking

Resources

• Napa Valley Vintners