White Wine Production
In White Wine Production, white grapes are pressed as soon as possible to minimize contact with the skins. The tannins imparted by these skins would overpower the more delicate flavors and aromas of white wine.
Deciding on a harvesting date for White Wine Production depends on the varietal and the style of wine. Some grapes are more acidic than others and need more time on the vine for sugar development. Other varietals are vinified into lower alcohol wines and do not need the same amount of sugar during fermentation. No matter what the grape type, balance is critical.
Destemming and Crushing White Grapes
Destemming and crushing white grapes is optional in the White Wine Production process. Some wineries treat white varietals in the same way that they treat red ones. These grapes can be macerated in their skins for up to two days to add body. But many wineries forgo this step altogether and immediately press white grapes.
Whether they are destemmed and crushed or not, pressing white grapes is a very gentle process that must be done carefully. If the grape bunches are left intact during this process, it is known as whole cluster pressing. This White Wine Production technique minimizes the amount of malic acid and tannins in the must.
Adding to Fermentation Containers
After pressing, the winemaker has another decision. What type of fermentation containers will be used? The style of the wine will dictate which container will be used. Oak barrels impart soft tannins and vanilla flavors. Stainless steel tanks allow the winemaker to control the fermentation temperature and produce crisp white wines. Wooden vats and concrete tanks are largely neutral.
Sulfur Dioxide Addition
After the grapes are pressed and the must is moved to the fermentation containers, sulfur dioxide is immediately added to prevent oxidation and spoilage. White wines generally require less sulfur than red wines.
The next step in White Wine Production is clarification. The must can be cooled for a period of time to remove excessive sediment. Fining agents can also be added at this time, which will remove the natural yeast.
Selecting Yeast Type
Once the wine is in its container and has been clarified, the winemaker adds a selected yeast type that has been cultivated in the lab. This gives him/her more control over the rest of the White Wine Production process.
White Wine Alcoholic Fermentation
Most white wine alcoholic fermentation takes place between 50 and 68 degrees Fahrenheit. The part of the process is longer and less intense than it is for red wines. This gives white wines the fresh, aromatic characteristics that they are valued for.
Barrel aging white wine only works for certain varietals, notably Chardonnay and Pinot Blanc. Some other white grapes are aged in barrels, but most rely on their fresh, fruity forward characteristics.
White Wine Malolactic Fermentation
One of the most important stylistic decisions a winemaker has is whether or not he/she will allow white wine malolactic fermentation. This process converts sharper malic acid to softer lactic acid. Because tart acidity frames most white wines, the majority of white wines skip this part of the White Wine Production process. Barrel aging and malolactic fermentation often go hand in hand.
White wines that undergo barrel aging and malolactic fermentation are often allowed to age for a period of time “sur lies.” This term refers to wines that are aged in contact with the dead yeast cells that remain after fermentation is complete. Some winemakers continually stir the lees during aging.
White wines that are not malolactically fermented undergo racking immediately after alcoholic fermentation is complete. Wines aged sur lies are racked after they have been aged sufficiently. No matter when racking is done, the sediments are allowed to settle at the bottom of the container. The wine is then siphoned off of the top and separated from the sediment.
Clarification & Bottling
After racking is complete, white wines can be further clarified using a number of White Wine Production methods. These include filtration, fining, cold stabilization and electrodialysis. All of these techniques make white wine visually brilliant, although some are more invasive than others.
After the wine is clarified to the winemaker’s specifications, it is time for bottling. Most wineries either own or rent bottling machines, but very small producers may bottle by hand. Inserting corks is next followed by adding the wine label.