Wine Production

Grape undergoes as long and pleasant travel in the period lying from vine stock to the wine. Grapes which are the most important component of the wine must have reached necessary maturation and be clean, fresh and dynamic to go such a travel. Wine has been an alcoholic beverage with an increasing consumption demand recently. It is increasingly preferred especially in social environments each passing day. During production of the wine, the yeast called as Saccharomyces cerevisia decomposes sugar, namely glucose in grape juice and converts it into ethyl alcohol during fermentation process. Thus, wine is formed. Although it is seen simple, there are many situations affecting odor and taste of the wine at the stage of production in fact. Certain differences come to the fore in productions of White Wine and Red Wine. However, the most important matter both in white wine production and red wine production: “Although the production technique or equipment is good, quality of the wine produced is determined depending on quality and feature of the raw material, namely grape.” You may see details of production of these two kinds of wine below.

Production of White Wine

1. Harvest:

Grapes must be processed freshly in production of white wine. Wine quality is directly proportional to the harvest made in accurate time. Sugar and acid amount are measured in order to find harvest time of grape. Sugar amount is measured by refractometer or hydrometer and acid percentage is measured by ph meter and acid kits. Harvest time of grape determines future of the wine. If grapes are picked very early, the wine becomes very acidic and colorless. There becomes deficiency in its aroma and taste. If they are picked very late, the wine becomes high alcoholic, low acidic and starts to lose its flavors. It would be useful to state here that it is not necessary to use only white grape in production of white wine. Black grapes may also be used because there is no residue, namely peel fermentation in production of white wine. Color is not formed since the thing giving its color to the wine is color agents in grape peel.

2. Separation:

The grape is separated from its stalks and straws before entering in the next process. If stalks and straws are not separated, the wine becomes bitter and dark colored. Bitterness is caused by tannins in the stalk and darkness is caused by the phenolic substances. Tannin agent is a substance giving acerbity to red wine. Therefore, while black grapes are taken directly to pressing process without separating from their stalks, white grapes are separated from their stalks.

3. Press:

It is the process applied to obtain grape juice. Only peel must be cracked. It is necessary not to break seeds and crush straws during press because seed contains tannin just like stalk and straws. A portion of the juice in grape is filtered automatically in this process and another portion may be obtained by a slight pressing. Grape juice derived from healthy grapes must be fermented after a slight sulphuration. Sulphurated juice is left for relaxation for 1 day and most of deposits and micro-organisms are caused to fall down. Thus, bad taste and odors do not pass to the juice.

4. Fermentation:

Fermentation process involves conversion of the juice into wine. The juice deposit of which has been taken is put into tanks. Tanks are not filled fully since there would be flooding during fermentation. Wine yeasts are added. Here, the aim is to ensure the sugar in grape to be converted into ethyl alcohol and carbon dioxide by yeasts. Start of fermentation is observed by release of carbon dioxide gas. Fermentation initially progresses fast. Then, it starts to slow down. Fermentation occurs fast for 1 week and slowly for 1-2 week(s). Temperature is very important in fermentation. The most appropriate temperature is about 25 degrees. If the temperature exceeds 30 degrees, yeasts start to function very fast and loss of aroma occurs.

5. Malolactic Fermentation:

Malolactic fermentation which may be implemented after alcohol fermentation may degrade the malic acid in wine. In this process, malic acid turns into lactic acid. Non-occurrence of this fermentation is ensured for the wines requiring acid. Malolactic fermentation is considered appropriate for the white wines to be aged in bottles.

6. Cooling - Keeping:

Wines, fermentation of which finish, have a blurred appearance. It is separated from its yeast and deposits by separation process. It is made subject to cooling process. Thus, maturation accelerates. Wine stone is caused to fall down and thus the crystal which may occur in the future is prevented. Nitrogenous composites also turn into deposit and fall down. Yeasts also fall down in the cooling process.

7. Filtration – Bottling:

When all the processes finish, the wine is ready for bottling. Filtration is made for the purpose of clarification of the wine and separation from rough particles and sent for bottling. Glass bottle is used in wine packages in general. Glass bottle protects quality of the wine better. Another important point in bottling is the cork. Quality of the cork is very important for preventing the contact of the wine and the air.

Production of Red Wine

In production of red wine, certain differences occur in comparison with white wine. These differences are discussed shortly below.

1.Stalk Separation: Stalk separation process is not performed in production of red wine in general because a sour taste is demanded in red wine. Sour taste is provided by tannin substances in stalks.

2.Residue Fermentation: It is applied to ensure color pigments in grape peel to give color to red wine. Ideal keeping time for this application (maceration) is 30 degrees.

3.Press: At this stage, colored juice is removed from the environment and the stage of alcohol fermentation is started.