The art of winemaking has been around for thousands of years. It’s a natural process which requires very little intervention from humans, but each winemaker will guide the process through various techniques. Generally, there are 5 basic elements to creating wine: harvesting, crushing and pressing, fermentation, clarification, and finally, ageing and bottling. Winemakers will follow these five steps but often add in their own variations along the way to help create their own unique wine.
The very first step in the winemaking process is to harvest the grapes. Grapes are the only fruit that has all the necessary acids, esters, and tannins to consistently make wine which is natural. Tannins are textural elements which make the wine dry and add bitterness to it.
The very moment the grapes are picked determines the acidity, sweetness and overall flavour of the wine you're making. So determining when to harvest requires a touch of science along with old fashioned tasking. The acidity of the sweetness of the grapes should be in perfect balance, but harvesting wine also depends heavily on the weather conditions. Producing English wine, therefore, requires closer attention to annual timings.
You can harvest by hand or mechanically, but many winemakers prefer to harvest by hand because mechanical harvesting can be tough on the grapes and vineyard. Once the grapes are taken into the winery, they are then categorised into bunches where the rotten or unripened grapes will be removed.
Crushing and Pressing
Once the grapes have been sorted, they are then ready to be de-stemmed and crushed. For many years, men and women did this manually by stomping the grapes using their feet. Nowadays, most winemakers perform crushing and pressing mechanically. Machines press the grapes into what is called 'must' which is simply freshly pressed grape juice that contains the skins, seeds and solids. Mechanical pressing has brought tremendous sanitary gain as well as increased the longevity and overall quality of the wine.
For white wine, the winemaker will quickly crush and press the grapes so that the juice can separate from the skins, seeds and solids. This is to prevent unwanted colour and tannins from leaching into the wine. Red wine, on the other hand, is left in contact with the skins in order to acquire flavour, colour and additional tannins.
After the crushing and pressing process is complete, fermentation then comes into play. The ‘must’ can begin fermenting naturally within 6 - 12 hours when aided with wild yeasts in the air. However, many winemakers intervene and add commercial cultured yeast to ensure consistency and help predict the end result.
Fermentation continues until all of the sugar is then converted into alcohol and dry wine is produced. To create a sweet wine, winemakers will sometimes halt the process before all of the sugar is converted. Fermentation can take anywhere from 10 days to one month or more.
When fermentation is completed, the clarification can then begin. Clarification is the process in which solids such as dead yeast cells, tannins and proteins are removed. Wine is then transferred into a different vessel such as an oak barrel or a stainless steel tank. Wine can then be clarified through fining or filtration.
Fining occurs when substances are added to the wine to clarify it. For example, a winemaker 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 ageing.
Ageing and Bottling
Ageing and bottling is the final stage of the winemaking process. A winemaker has two options here: bottle the wine straight away or let it have some additional ageing time. Further ageing can be done in the bottles, stainless steel tanks, or oak barrels. Ageing the wine in oak barrels will produce a much smoother, rounder and more vanilla flavoured wine. It will also help increase 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 the ageing process is finally complete, the wines are then bottled with either a cork or screw cap, this is all depending on the winemaker's preference.