Viticulture 101

How Wine is Made - Winemaking

After Harvest

Once grapes have been harvested, they begin their journey towards becoming wine. The harvested grapes are taken to the processing facility to be made into wine.

Traditional Dry White Wine Production

White grapes go through the quickest process of winemaking. From the field, grapes make their way to the production facility. They are run through a crusher which breaks the grapeskins in order to extract as much juice as possible.

After crushing, the grapes are pressed. The juice extracted is clear This extracted juice is then sent for alcoholic fermentation. During alcoholic fermentation, yeast processes sugar in the grape must. The processed sugar becomes alcohol, carbon dioxide, and heat. Once alcoholic fermentation is completed, the new wine is sent to storage and possible maturation prior to being packaged.

Traditional Dry Red Wine Production

When a red wine is produced, it starts in a similar way to white wine. Red grapes are first crushed. After crushing, alcoholic fermentation begins while the skins of the grapes remain in contact with the white juice from the pulp. This process is known as maceration. During maceration, the carbon dioxide produced in fermentation will push grape skins to the top of the fermenting vat. Various methods of cap management need to be undertaken. The most common method is known as Punching down, where a plunger is used to push down the grapes. Another method, known as pumping over uses gravity driven juice from the bottom of the fermentation tank to cover grapeskins.

After fermentation and maceration have concluded, the grapes are pressed. The wine is then sent for storage and maceration before eventual packaging for sale.

Creating Sweet Wine

Sweet wine can be produced in a number of ways. 

Late Harvest

Grapes can be left on the vine and allowed to shrivel in a late harvest style. This is common in Germany where the wines are rated on their ripeness category. As the grapes shrivel, their sugars concentrate.

Noble Rot

Under certain conditions, the gray rot Botrytis cinerea which will usually be detrimental to grapes can be quite interesting in other circumstances. As Botrytis develops, it will pull moisture from the grapes. This concentration of sugar allows for the production of beautifully nuanced sweet wines.

Mutage

In the case of producing sweet wines, sometimes fermentation is arrested. This is done through a process called mutage. To initiate mutage, distilled grape spirits (usually pomace brandy) is added into fermenting grape must to kill yeast and keep a high level of sugar.

Drying

In a similar function to late harvest, grapes can be dried out. This is called straw wine. In Italy appassimento or in France passerillage these wines are produced by picking grapes and then purposefully drying them out.

These are the main ways to produce wine. Don’t worry, there are more ways to make wine.