How Wine is Made
How wine is made There is an impression that wine is a very complicated drink. In fact, it is one of the easiest alcoholic drinks to make – as long as you have all the right conditions and ingredients.
Step 1 - Grapes
Red and rosé wines are produced from black grapes, however white wines can also be produced from white and black grapes.
After analysing the sugar levels and assessing their maturity, the grapes are picked – harvesting takes place at different times due to the climate:
Harvest in the Northern Hemisphere – begins end of August, but in cool regions such a Germany it can be as late as late November.
Harvest in the Southern Hemisphere – South Africa harvest begins at the end of January, Australia and Chile in February/March and New Zealand in late April, due to the cooler climate.
Step 2 - Crush
Grapes are usually destalked for both red and white wine. Crushing breaks the skin of the grapes and allows the juice to run out.
Step 3 - Press
Separating the liquid and grape pulp is achieved by pressing. In the case of white wine, pressing occurs before the start of fermentation, while for red and rosé wines it will be after a period of contact between the juice and skins to achieve the desired colour and tannin levels.
Step 4 - Ferment
Yeasts are naturally present on the skins of grapes and around the winery, so once the grapes are crushed, fermentation will start naturally. However, winemakers often select cultivated yeasts that are best adapted for the wine being made. The yeast feeds on the sugars, converting it to alcohol.
A second fermentation reaction takes place on all red and some white wines. This involves naturally occurring malic acid converting to lactic acid, which in turn softens the wine and gives it the broader texture.