Winemaking, or vinification, is the art of turning a sweet grape into an alcoholic and aromatic liquid. The secrets of this transformation have been known for a really long time. In the Eastern European country of Georgia, traces of wine over 6,000 years old have been discovered in jars. But how exactly is wine made?
It All Starts On The Vineyard…
Making a great wine is not unlike making a great meal. If you use the right ingredients, chances are you’ll end up with a good dish. If they are of poor quality, all your efforts would go down the drain. The secrets of winemaking lies in good quality and ripe grapes harvested at the right maturity.
…Where The Maturity Of Grapes Are Evaluated
The maturity of grapes are evaluated using a refractometer, a tool that determines the amount of sugar. And of course the taste buds and experience of the winemaker also come into play when it comes to judging the acidity rate and concentration of aromas and tannins.
There are two types of maturity:
- Technological maturity: A balance struck between the sugar level and a well-defined acidity. Primarily for sparkling wines.
- Phenolic maturity: For white and red wines. In this case, the grape’s skin must be fine, coloured, and with taste. Grape seeds must be brown, and sugar level must be sufficient; between 200 to 250 grams per litre!
Moving Into The Wine Cellar
Once grapes are properly ripened, they have to be efficiently picked and taken to the wine cellar. Picking is done either by hand to preserve the integrity of the grapes, or by machine which has the main advantage of being fast and economical.
Steps Involved In The Wine Cellar
The grapes are loaded in presses which extract their juice contained in the pulp of the grapes. This step is essential because it is a question of extracting juice in the gentlest way possible without extracting the bitterness contained in the grape bunches. This process takes about 4 hours.
During this step, the “liquid” phase (grape juice) is separated from the “solid” phases (skin, remaining pulp etc) to obtain a clean juice which will not carry a herbaceous or vegetable taste. It can either be left to decant at ambient temperature or in the cold for 24 to 48 hours to obtain two distinct phases. The clear grape juice is then filled into tanks for the next step.
3) Alcoholic fermentation
This is where the magic of wine comes in. Grape juice, with a little help from yeast, will turn into alcohol. And that’s not all. Aromas attached to the sugar of the grape juice are consumed by yeast, which will then be released and the wine will reveal all its aromatic potential.
Different parameters such as temperature or acidity will play a part in the development of bacteria, and thus allowing us to create a multitude of different wines. Here, the science and experience of the winemaker is most crucial. This is especially so for Alsace wines which are mainly composed of aromatic grape varieties.
4) Malolactic fermentation
This is more a transformation than an actual fermentation process where malic acid (double acid) is transformed into lactic acid (simple acid). This is a form of natural deacidication made by lactic bacteria – just as in yoghurts – and is actually not always desired by the winemaker.
Why? Because butter, milk or yoghurt flavours can appear and mask the main aromas of Alsatian grape varieties. Therefore this type of fermentation is practised sparsely on Alsatian white wines.
To create a great wine, a winemaker’s work is never done. They must find the right balance between acidity, sugar and alcohol levels, among other parameters. Winemakers taste their wines constantly during this process to make sure they find this balance, as well as the right moment to stop the malolactic fermentation (or let it finish if they desire a dry wine).
Racking is another step of settling, done right after fermentation. Wine is separated from the lees, which are remnants of dead yeasts. The “clear” wine is then transferred to another tank for aging.
The fine lees are often pumped with the clear wine so that the noble part of the yeasts will “enrich” the wine and make it more fat and complex. Coarse lees can cause unwanted odours like rotten egg, cabbage or onion! They are therefore sent to the distillery to recover alcohol and acids for future use, for example in cosmetics.
The aim here is to preserve the wine so that it can be improved and eventually bottled. In Alsace, the geological diversity is such that in the same vineyard, plots separated by only a few miles can produce completely different wines.
Hence, once again, the experience and know-how of the winemaker is very important. They may either bottle the wine or let it age for several months in tanks, vats or barrels in order to find the perfect balance between the aromatic side of the Alsatian grape varieties, the soil on which it has grown, and the taste of consumers.
Once this balance has been found, winemakers will wait patiently for the wine to age. Here the fine lees contribute to the wine and amplify it by melting the acidities and replacing the bitter ones.
Once the wine is ready, it will be filled into its final packaging. But before bottling, even the choice of cork has to be considered – Should it be a traditional cork that lets the wine breathe? A plastic cork, guaranteed to avoid cork taint? Or a screw capsule, trendy while retaining the wine’s aromatic freshness? This last step definitely the peak after a year of hard work!
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