I got to experience the harvest season for South African wineries, and what goes on in the cellar before we finally get our wines. South Africa is located at the tip of Africa, with most wine regions located near the coastal influences of the Atlantic and Indian Oceans, combining good soil and weather conditions for growing good vines for wine.
During the harvest months of February and March, the average daily temperatures in many South African wine regions is 23 °C with spikes up to 40 °C. I experienced both the cold and the warm weathers during my stay, and I also found out that the harvest varies from wine region to region and from grape to grape.
As part of the learning process, I realized that winemaking could be broken into these 5 major steps!
Harvesting
Harvesting is the first step in the wine making process and an important part of ensuring the quality of wine. Winemakers often use the sugar and acid levels of the grape as a guide in determining ripeness. The moment the grapes are picked determines the acidity, sweetness, and flavor of the wine. Determining when to harvest requires a touch of science, and well, some old-fashioned tasting. The acidity and sweetness of the grapes should be in perfect balance, however harvesting also depends on the weather.
Hand pickers at Le Grand Chasseur Wine Estate
Harvesting can be done by hand or mechanically. A mechanical vine harvester works by beating the vine with rubber sticks to get the vine to drop its fruit onto a onto a conveyor belt that brings the fruit to a holding bin. The machines are not able to distinguish grape clusters from mud, leaves and other particles. However proper sorting out of healthy grapes and unripe or rotted bunches are carried out at the winemaking facility.
One of the benefits of mechanical harvesting is the relatively low cost. A harvester is able to run 24 hours a day and pick 80-200 tons of grapes, compared to the 1-2 tons that an experienced human picker could harvest.
Despite the costs, some wineries prefer the use of human workers to hand-pick grapes. The main advantage is the knowledge and discernment of the worker to pick only healthy bunches and the gentler handling of the grapes.
Two of the Wine Estates I visited, Le Grand Chasseur Wine Estate and Weltevrede Estate combine both handpicking and the use of the harvester depending on the type of grape and the type of wine intended.
Crushing and Pressing
After the grapes are harvested, they are sorted and ready to be de-stemmed and crushed. Mechanical presses stomp the grapes into a must (freshly pressed grape juice that contains the skins, seeds, and solids). For white wine, the wine maker will quickly crush and press the grapes in order to separate the juice from the skins, seeds, and solids. However for red wine, it is left in contact with the skins to acquire flavour, colour, and additional tannins.
Fermentation
Once the crushing and pressing is over, it is then time for fermentation. Yeast is added to the must for fermentation, to ensure consistency and predict the end result. Fermentation continues until all of the sugar is converted into alcohol and dry wine is produced. To create a sweet wine, wine makers will sometimes stop the process before all of the sugar is converted. Fermentation can take anywhere from 10 days to one month or more.
Clarification
Once fermentation is complete, solids such as dead yeast cells, tannins, and proteins are removed. This process is called clarification. Wine is transferred into a different vessel such as an oak barrel or a stainless steel tank. The wine can then be clarified through fining or filtration. Fining occurs when substances are added to the wine to clarify it. For example, a wine maker might add a substance such as clay that the unwanted particles will adhere to. This will force them to the bottom of the tank. Filtration occurs by using a filter to capture the larger particles in the wine. The clarified wine is then racked into another vessel and prepared for bottling or future aging.
Aging and Bottling
The final stage of the winemaking process is aging and bottling. Further aging can be done in the bottles, stainless steel tanks, or oak barrels. Aging the wine in oak barrels will produce a smoother, rounder, and more vanilla flavored wine. It also increases wine’s exposure to oxygen while it ages, which decreases tannin and helps the wine reach its optimal fruitiness. Steel tanks are commonly used for zesty white wines.
After aging, wines are bottled with either a cork or a screw cap, depending on the wine maker’s preference. And contrary to popular believe a cork or a screw cap does not determine the quality of the wine.
Note that sparkling wines or bubblies do undergo a further step. South African sparkling wines made in the traditional French method (methode champenoise) are referred to as Methode Cap Classiques or MCC’s. Wine that has been impregnated with CO2 bubbles is simply termed sparkling wine whereas MCC’s undergo a second fermentation in the bottle to create the sought after bubbles.
To make a MCC the winemaker first makes a base wine in the normal manner and, once bottled, the ‘liqueur de tirage’ is added. This mixture of wine, yeast and sugar starts the second fermentation process in the bottle. This time the CO2 is not able to escape as with a still wine, but forms the bubbles that are captured inside the bottle.
After the second fermentation sediment is formed in the bottle and needs to be removed to produce a clear, sparkling wine. This process involves turning the bottles in boards with specially shaped holes every day for a few weeks. Each turn tilts the bottle more and more on its head until all the sediment is collected in the neck of the bottle.
To eject the sediment the necks of the bottles are placed in a very cold brine bath, which freezes the sediment. The bottle top is then removed and the pressure shoots out the ice cube of sediment. This process is known as degorgement. Before corking ‘liqueur d’expidition’ is added to top up the bottle.
So there you have it! The next time you pick up a bottle of South African wine, this is the process it went through! Cheers!
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