Vinification is the process that transforms the grapes into wine. The process of vinification differ from region to region, financial state of the winery and the grape types. The harvesting time and the type of oak used for aging are based on the region in which the wine grapes are grown.
Regardless these factors wine making process involves the following stages:
Narrow and Tall Bottles
These types of wine bottles are used to store Rhine, Mosel and Alsace wines. These bottles either have little or no punt. The bottle will be hollow at the bottom.
More than any other thing, the grape quality determines the quality of wine. The quality of grape is mostly affected by the growing season, weather, soil, acidity, harvesting time and the pruning method.
In the northern hemisphere the grapes are harvested from early September till early November. In the southern hemisphere it is harvested during Mid-February till early March. In the cool areas of southern hemisphere the harvesting time extends up to May.
The first step in wine making process is Harvesting or Picking. Grapes should be harvested at the right time in order to make good wine. Harvesting can be done either mechanically or by hand. Still the wine makers prefer to harvest in hand since the mechanical harvesting can often be tough on the vineyard and grapes. After harvesting once the grapes return to the winery, they are sorted cutting out the rotten ones and the under ripped fruits before crushing.
The process of separating the grapes from the stems and cluster parts is called Destemming. Some of the wine makers keep some fragments of the stem to increase the wine tannin. This can also be done manually or by mechanically. Manual destemming increase the quality
After destemming the grapes are crushed to extract the juice from the skin. This is done before the fermentation process begins. In the olden days bare feet is used to extract the grape juice, now a day machines like crushers are used.
During the process of crushing excess care has to take to prevent skin tearing too much. Too much of skin tearing will increase the tannin content which is not good for white wine grapes. Skin tearing will also cause the grape juice to over oxidize which is an unwanted occurrence. Grapes like Pinot Noir and Syrah are partially crushed to preserve their fruity flavor.
Pressing the Grapes
Separation of grape juice and the skin is named as pressing. After crushing the grape juice will flow freely, selected wineries use pressers to make sure maximum juice is released. The more force the more tannic the wine will be.
Once the grapes are pressed they are introduced into the process of fermentation. During this process the grape juice are converted into alcoholic beverage. The yeast interacts with the sugar in the grape juice and converts them into ethanol and carbon dioxide. The fermentation temperature and the speed of fermentation are the important concerns in this process.
There are two distinct stages in wine fermentation. They are Primary Fermentation (Aerobic) and Secondary Fermentation (Anaerobic).
Primary fermentation will last for the first 3 to 5 days. Mostly 70 percentage of the fermentation process will take place in the first few days. Considerable amount of foaming may be seen during this rapid fermentation. In the primary fermentation the fermentation vessel is left open to the air, since air plays a very important role in the yeast cell multiplication.
The remaining 30 percentage of fermentation take place during the second part. The secondary fermentation will last for one to two weeks. The secondary fermentation time depends on the amount of nutrient and sugar available. In secondary fermentation the air exposure should be kept the minimum. This done by bestowing an air lock to the fermentation vessel, this is done because to make the yeast forget about multiplying and to make them to release their energy fully to make alcohol.
Purifying and Refining
After fermentation purifying and refining of wine take places. Here any solid parts that are left after fermentation are removed. To remove the residue wine makers pour the wine in a filter. Simultaneously, during this process wines will be combined with other types of wine to produce preferred flavor, tannin and acidity.
Once the wine is purified and refined, they are preserved with sulfur dioxide or potassium sorbate. During the natural process of fermentation a minimum amount of sulfites are produced, but more is added for the use of commercial preservation.
Wine preservation is very important since bacterial can easily decay the wines without any preservatives. The preservatives added to the wine form an anti-oxidation or anti-microbial agent. These agents stop the ongoing malolactic fermentation.
Wines are aged for a particular amount of time to get more welcoming wine. Once after purification, the wines are moved to wooden barrels for aging. Metal vats, concrete vats and glass carboys are also used in some cases to increase the flavor. During aging wine softens and it will be slowly oxidized.
After aging, the wines are bottled. During the process of bottling a final dose of sulfite is added to the wine to prevent it from uninvited fermentation in the bottle. The bottles are then sealed with cork and screw caps. As a final step capsule is added to the top of wine bottle, which is at last heated to get a tight seal.