Alongside the grape growing environment, what happens in the vineyard is equally as important for wine style and quality
There are certain factors and processes that are common to all wines, however the roles they play, and the decisions taken by the winemaker in production and maturation are key.
For all winemakers, harvest is the most critical time of the year, it can also be very tense. Timing is everything.
Grapes picked too early may result in tart and thin-tasting wines.
Grapes picked too late may result in wines that taste overly ripe and flabby.
NOTE - harvest can be by hand or machine
Crushing, De-Stemming & Pressing
As soon as the grapes arrive in the vineyard, they either have their stems cut and are pressed or kept are as whole bunches and pressed. Stems add tannin but also reduce sourness.
The difference between red and white wine production is that red wine is fermented with the skins on but for white wine the skins are separated from the juice before fermentation.
NOTE - red wine has to be produced from red grapes BUT white wine can be made from red or white grapes.
Yeast is added to the juice. They consume the grape sugars and make alcohol. There are two types of yeast used; those naturally occurring in the juice (from the skins) or “packet” yeast (like you’d find in bread making.
Using controlled yeast allows the winemaker to produce consistent wines, whereas natural wines are more challenging but result in interesting tasting wines.
Fermentation of white wine takes place at cooler temperatures than for red wine and is approx. 7 - 21 days.
Grape skin gives lots of colour and flavour and so it is important to pumpover or punchdown the skins so they stay in contact with the juice.
The winemaker can control the sweetness of the wine by stopping the action of the yeast and the fermentation.
Pressing the Grapes
After the fermentation, vintners drain the freely running wine from the tank and put the remaining skins into a wine press. Pressing the skins gives winemakers about 15% more wine!
Malolactic Fermentation (MLF)
The winemaker can choose to allow malolactic fermentation by bacteria. This is the conversion of tart malic acid into creamy lactic acid.
This lowers the acidity, reduced fruitiness and adds creamy flavours.
If the desired wine is crisp and fresh then this will usually not take place. MLF is common in most red wines but only a few whites e.g. Chardonnay.
Stirring the Lees
After the fermentation, wine stays in barrels or tanks and is stirred. This stirring causes the dead yeast particles (lees) to float into the wine. The less adds flavour and gives a creamy texture (think the taste of beer or bread). The choice of maturing vessel affects the characteristics of the end wine.
This is the step where the winemaker my choose to blend wines from different grape varieties. This is dependent on the type of wine they are trying to make. Grapes can be blended to add acidity, tannin or certain aromas.
At this stage the wine is still cloudy so clarifying or fining agents, casein or egg whites, are used to remove the proteins.
NOTE - this is why some wines aren't suitable for vegans
Wines age in a variety of storage vessels including oak barrels, concrete, clay, and stainless steel tanks. Each vessel affects wine differently as it ages.
Bottling and to Market
For most white wines, the time to market is much less than red, because whites are loved for their fresh, fruity and floral flavours – all of which come through freshness, not age.