Produced in a similar way to red wine, white wine is made exclusively from the near colourless flesh of grapes. White wine is made in a myriad of styles from light, dry and crisp to dark, heavy and sweet and all styles between. Unlike red wine, which has to be made from black grapes, white wine can be made from black grapes – careful crushing and pressing with minimal skin contact ensures that a minimal amount of colour is leeched from the skins and the resultant liquid maintains a greenish yellow hue.
White wine production involves the following stages:
Grapes are picked when the desired ripeness has been reached
Stems and leaves are removed either by hand of mechanically
The grapes are then crushed. The juice along with the crushed grapes, seeds and skins is referred to as the must.
Skin contact is not required as no colour needs to be extracted so the must is then pressed and allowed to settle.
At this stage the juice has not undergone fermentation and will be cloudy due to lees that are suspended in it. Settling allows the separation of these particles. Some white wines are matured on their lees to increase the body and richness of the wine
The settled juice is transferred to a tank made from stainless steel or concrete or an oak barrel. At this stage winemakers will either allow fermentation to start spontaneously due to naturally occurring yeasts or they will add specific yeasts to enable them to control fermentation more precisely. Tanks are often kept cool to allow the development of certain flavours in the final wine. If a sweeter style of white wine is required fermentation is stopped so that residual sugar remains. Fermentation can be stopped in a number of ways included yeast filtration and fortification with spirit.
Not all white wine undergoes this step but it is reserved for those wines that require a lower level of acidity. The process transforms malic acid into the softer lactic acid.
White wine may be matured in tanks, oak barrels or bottles. During the maturation process the lees may be stirred in a process called battonage which increases the wines body and complexity.
At this stage it might be desirable for the winemaker to clarify their wine. This process involves introducing an agent, such as bentonite, to remove any remaining particles in the wine.There are other processes such as stabilisation, filtration and conditioning that white wine may go through to make it ready for sale. Traditional producers tend to eschew these stages as it can have a negative impact on the flavour of the finished white wine.
White wine is made from a multitude of grape varieties from all over the world and certain grape varieties grown in particular places can produce highly distinctive and desirable wines. Famous examples include: Chardonnay from Burgundy, Riesling from Mosel, Semillon from Bordeaux, Sauvignon Blanc from Loire, Viognier from the Rhône Valley and Sauvignon Blanc from New Zealand.