Making white wine is an old and special skill. People have been doing it for a very long time. Even though red wines often get more attention, white wines have their own unique tastes and smells. But how exactly do we get these amazing white wines? The answer is in the careful process of turning grape juice into fermented grape juice, or what we know as white wine. In this article, we’ll talk about how white wine is made, step by step.
Starting In The Vineyard
All wine comes from grapes, which are planted and grown on vines in a vineyard. White wine specifically comes from white grapes, whereas red wine comes from black grapes or red grapes. Common white wine grape varieties include Chardonnay, Riesling, Sauvignon Blanc, and Pinot Gris, among many others.
When the grapes are ripe, they are harvested and begin their journey from the ground into the bottle. First, the winemaker determines whether the grapes are ready for harvest by studying their acid, tannin, and sugar levels. Then, the grapes are picked, either manually or by machine, and sorted. In this process, the grapes are sorted from non-grape material to be prepared for pressing.
Pressing
With the fruit sorted and cleaned, the next step is to press, which takes the juice from the grape. Pressing machines like the traditional basket press push down on the grapes until the juice is fully released. Other presses, like the pneumatic press, use pressure to squeeze the grapes dry, leaving behind just the pomace or remaining solid grape matter.
Because most white wines are made with minimal skin contact (to keep their light color and crisp flavors), most machines are designed to press the grapes to get the most juice out of them without getting too much of the grape skins (tannins).
As the grapes are pressed, the clear juice is transferred to a tank to settle and prepare for fermentation. Many white wines are kept in stainless steel tanks, but some are kept in concrete or glass tanks. If a wine is oaked, like a Chardonnay, it can be kept in an oak barrel to ferment.
Fermentation
Once the wine is in its container, yeast is added to begin the fermentation process that will ultimately transform unfermented juice into wine. When yeast mixes with grape juice, it turns the grape sugar into alcohol. It also uses up oxygen and makes carbon dioxide and heat.
The winemaker helps this happen by changing the temperature, mixing it, letting in air, and sometimes giving the yeast more food. This continues until almost all the sugar becomes alcohol. Most white wines are fermented at a cool temperature, usually at or below room temperature, whereas red wine is generally fermented at warmer temperatures.
Winemakers continuously monitor the wine during this process, checking the nutrient level and temperature to ensure the wine’s quality is kept at a maximum.
There are dozens of yeasts to choose from. Some winemakers, particularly those making natural wines, use natural yeasts as opposed to commercial yeasts. The natural yeasts can produce a more complex flavor profile but are also unpredictable and are not commonly used.
Secondary Fermentation (Malolactic Fermentation)
Some winemakers choose to have their white wines undergo a secondary fermentation, where stronger malic acid is converted into a smoother lactic acid through bacteria, thus giving the wine a creamier finish. This is more common in wine like Chardonnay, where secondary fermentation can give a buttery, creamy note. It is not commonly done for sharper wines like Sauvignon Blanc or Riesling.
In sparkling wines, a secondary fermentation occurs. However, the wine is sealed, and thus the carbon dioxide that is created cannot escape and turns into bubbles.
After fermentation, leftover sediment (lees) is generally removed as the wine is prepared for storage.
Maturation
On average, white wines are ready “sooner” than red wines, however, they still need to be aged properly. White wines can be aged in wooden barrels, concrete, stainless steel, and other vessels, which each contribute different qualities to the wine.
Stainless steel vats are neutral. They impart no outside characteristics to the wine and are ideal for temperature and oxygen control. This is the way the majority of white wine is matured and stored.
Some white wines are matured in oak barrels, which bring tannins into the wine. They also allow for some oxygen to pass into the wine. The vessel used for maturing depends on how the winemaker wants the finished product to taste.
Stabilization
Most white wines will be stabilized. This means sulfites may be added for protection against oxygen. Both head and cold stabilization methods add to the wine’s longevity and clarity.
Bottling
With the winemaking process complete, the final steps include a final filtration and bottling. Some wines are bottled and left to mature for a while while most white wines are best enjoyed young.
Conclusion
Learning the process of white winemaking can help us enjoy it even more. From picking the grapes to pressing and fermenting them, making white wine needs both skill and care. When you drink white wine, you’re not just having fermented grape juice. You’re enjoying a drink that comes from years of practice and the special qualities of where the grapes are grown. So, the next time you have a glass of white wine, think about all the work that went into it.
