winemaking process

Winemaking process: How is the wine made?

Winemaking is an art, starting from the selection of grapes, harvesting them at the right time, fermenting them for the correct time, and finally bottling and releasing them. The whole winemaking process involves a lot of effort and patience and the result is shown in the quality of the wine output. The study of wine and winemaking is known as Oenology and the winemaker is known as the vintner.

The first and foremost step in the winemaking process is the selection of grapes. Not all wines are made from grapes. We also have wines made from honey, known as the mead wine and there are fruit wines made from different varieties of fruits. For example, we have orange wine where the wine is made from orange juice instead of grape juice. Fruit wines are alcoholic beverages made from different fruits other than grapes. Fruit wines are popular wines made from the home winemaking process.

grapevine

Though wines are made from different ingredients, grapes are the main source of the traditional winemaking process. The process of cultivating and harvesting grapes is known as viticulture and we have many different varieties of grapes. The selection of grapes and their fermentation changes with the type of wine produced. Hence the red winemaking process is different from the white winemaking process.

Winemaking process step by step

Winemaking process is divided into the following series of steps,

1.Harvesting,

2.Crushing,

3.Pressing,

4.Fermentation,

5.Aging,

6.Bottling.

Let us see all these steps in detail,

1.Harvesting

Viticulture or winegrowing is the basis of the winemaking process, the vintners consider various factors while growing the grapes, like,

1.Looking for the pests and diseases which have a serious effect on the yield of the vines.

2.Checking the ripeness level of the grapes, when to harvest the grapes and how long they should be remaining on the vine plays an important role in the winemaking process. Again this decision is taken by the vintner after discussing with the winemaker about the style of the wine.For example, Sweet wines need the grapes to stay for a longer period of time on the vines.

3.Pruning the vines during winter months, removing the unwanted and unneeded branches and other tissues from the crop increasing productivity.

4.Removing the green and immature grapes from the clusters allows the other grapes to reach the ripening stage fully resulting in a healthy harvest, this process is known as Green harvest and is mainly used to improve the quality of the wine without getting diluted by unripe grapes.

Grape vines

Grapes are often found as clusters on the wines, some are long clusters that are lengthy and some are short clusters. The ripeness level also is different in different grapes, some clusters ripe evenly while in some other clusters each grapes’ ripeness is different from the other. Pollination and fertilization are the results of the formation of seeds in the grapes, and the seedless grapes are often used as raisins. Each plant yields approximately 100 to 200 grapes.

The skin of the grape plays a major role in the winemaking process. The thickness of the grapes varies with the variety. Some grapes like Cabernet Sauvignon, Merlot, Petite Sirah have thick skin, while Pinot Noir, Cabernet Franc, and Sangiovese have thin skin. Grape skins have high tannins in them. A small number of tannins are also present in the grape must. Tannins play an important role in the aging of the wine. They are good for health and are highly functional in making the color and structure of the wine.

Climate also has a significant effect on wine characteristics. According to sources grapes need a maximum of 1300 to 1500 sunlight hours for full development. Generally, warm summers are best for growing vines balancing the sugars and acids in the wine. Spring and fall seasons are not recommended as the rainfall and the weather during these seasons affect productivity and grapes are often spoiled with fungus attacks.

Grapes that are grown in warmer climates, often ripen fast resulting in sweeter wines with less acidity. Grapes from the cooler regions ripe early resulting in fresh wines with high acidic content.

The soil in which the grapes are grown has a significant effect on the quality of the wine. Soil near rivers has rich mineral content and the grapes grown are fertile resulting in the production of high-quality wine. Grapevines grown on the slopes and hillside terrains are the best compared to grapes grown on flat terrain, the reason being the uniformity of the sunshine over all the grapes and the soil also gets protected from getting over moist.

Slope vineyard

How many grapes are used for making wine?

winemaking process grapes

Harvesting Methods

Wine characteristics are determined by the grape quality and the variety that is cultivated by the vintner. There are many varieties of grapes that are used in the winemaking process.

A varietal wine is a wine that is developed with one single available grape variety and that name is shown on the wine label. However wines are also made by blending two varieties of grapes from the same harvest, the result is the fine blend wine. For example, the sparkling wines are often a blend of  Pinot Noir, Chardonnay, and the Pinot Meunier grapes.

The time of the harvest is often left with the winemaker and his choice of the style of the wine,

Based on his decision and based on the level of ripening, the grapes are harvested for the proper balance of sugars, acids, and, tannins.

Ripeness level

The ripeness level is often measured by the sweetness and acid levels in the grape. Vintners often use a refractometer for testing the sweetness level in the grapes and titration tests for knowing the acid levels in the grapes.

Season

The harvesting season differs with the locality of the vineyards. In general the areas in the northern hemisphere close to the equator, the harvesting season falls from August to October and in the southern hemisphere, the harvesting happens from February to April.

Methods

Harvesting is done either,

1.Mechanically, or by

2.Handpicking

A mechanical harvester collects the grape clusters in the bin by beating the vines with rubber sticks. The process is very fast compared to the traditional hand-picking of the grapes, but the problem is, the grapes often lose their skins in the process. Also, the unhealthy and unripe grapes also combine with the healthy grapes which have to be sorted again. However, because of less labor, this harvesting mechanism is economical.

winemaking process grape harvesting
mechanical harvesting

Handpicking harvesting mechanism is best suited for slopes and hillside terrains where mechanical harvesting is not possible. They are often advantageous as only the high-quality grape clusters are chosen to be picked. Also in the case of botrytized sweet wines like sherry the grapes are often sweetened by noble rot, handpicking allows such grapes to be identified and harvested.

winemaking process handpicking grapes
Handpicking grapes

2.Crushing

Crushing is the process where the grapes are crushed to make the skins and grape must separate. The stems of the grapes are removed through the destemming process. However, for the white wine production, the grapes are crushed with the stems so that the skin gets separated along with the stem. In red wine production, the red wine grapes are destemmed and the grapes are crushed. Stems that are brown in color have a high amounts of tannins in them. Sometimes when the winemaker feels that the tannins in the wine are not enough, they add the stems also in the fermentation process.

winemaking process barefoot crushing

In the traditional winemaking process, grapes are crushed barefoot, this process is good for small-scale winemaking. Now also in some wine tours, they are offering barefoot grape stomping to attract visitors. Grape treading or grape stomping helps in the crushing of the grapes in a gentle manner without crushing the seeds.

Now we have mechanical rollers that crush the grapes in a large quantity.

winemaking process crushing

This step of the winemaking process is also known as maceration, where the phenolic compounds, tannins present in the grape skin, seeds, and stems are passed to the grape must. Maceration gives color to the wine, red wine gains its color because of soaking the juice with the skins. White wines do not have such color as the skins are not allowed to stay with the grape juice prior to pressing.

3.Pressing

The next step in the winemaking process is pressing. The crushed grapes contain some free-run juice that is formed during the crushing process before getting pressed. This free-run wine is of high quality and is generally used during vinification. The remaining skins and grape must along with the seeds and the stem are pressed for the extraction of the grape juice.

winemaking process pressing

When should you press red wine?

Pressing is done differently in red wines and white wines. In the case of red wines, pressing happens after the primary fermentation takes place. During the primary fermentation, the crushed grapes and free-run juice are allowed to ferment. Yeast is present in the grape skin naturally which uses the sugars in the grape must naturally. In the case of white wines pressing is done before the fermentation. The grape juice gets separated from the skin and is fermented later. In the case of Rose wines, the juice is fermented along with the skin of the grapes up to some time until the desired color is reached.

4.Fermentation

The next important step in the winemaking process is fermentation. The fermentation process converts the sugars into the grapes into ethanol and carbon dioxide.

For the process to take place it needs yeast. Yeast eats up the sugars present in the grape must and multiplies producing alcohol. Fermentation occurs in many stages.

How do you make wine with out yeast?

We can make wine without yeast because there is some natural yeast present on the skin of the grapes. It is observed as a powdery substance on the grapes.

Primary fermentation occurs with this natural yeast that is present on the grape skin. In some cases where the yeast is not enough, cultured yeasts are also added.

In some cases, the fermentation is stopped forcibly or the fermentation fails to take place completely, then a good amount of sugars remain in the grapes resulting in the production of sweet wines. The winemaker who wants to produce dessert wines or sweet wines will stop the fermentation either by decreasing the temperature of the grape must, preventing the yeast from eating the sugars or by filtering the yeast. In the case of fortified wines, alcohol like brandy is added to the wine to kill off the yeast.

Sweet wines are liked by all and are the best for beginners to start the wine journey. But they are high in calories and are not good for health and fitness.

For the yeast to produce alcohol it needs a good amount of sugar to survive. For every gram of alcohol to get produced the yeast needs two grams of sugar, which means to have the ABV(Alcohol By Volume) 12 percent we need 24 grams of sugar in the grape juice. The sugar concentration in the grape must is measured by a device, Sacccharometer.

If the sugars are not enough for the yeast to multiply and to result in the required alcohol percentage, additional sugars are added during the process of fermentation. This process is known as Chaptalization.

How long does the wine fermentation take?

The process of fermentation generally happens in two to three weeks and the primary fermentation takes three to seven days.

Temperature also plays a very important role in the process of fermentation. White wine is fermented at a temperature of 18- 20 degrees, whereas red wine is fermented at a higher temperature of more than 29 degrees.

As fermentation is a chemical process, heat gets generated inside the wine during the whole process. Hence fermentation is generally carried out in steel tanks.

 fermentation in steel tanks

What happens during the fermentation?

During fermentation yeasts or micro organisms break down the sugars and starches into ethanol and acids, helping in the preservation of wine for a longer period of time. The probiotics in the fermented wine helps in maintaining a healthy gut.

Secondary Fermentation

During secondary fermentation, the yeast eats up all the sugar, and the alcohol percentage in the wines increases. Yeast gets killed off leaving the wine with the desired alcohol content. The process of distillation removes the water in the wine leaving behind the concentrated wine.

In some white wines and almost all red wines, cultured yeasts are added to reduce the malic acid present in the wine and to improve the taste of the wine. The process is known as Malolactic fermentation. The malic acid that was bitter and harsh gets turned to gentle and less sour lactic acid. Lactic acid is generally found in dairy products. The buttery taste of chardonnays is because of this fermentation.

5. Aging

In the next step of the winemaking process, the wine is allowed to undergo secondary fermentation. In this process, the wine gets transferred to another vessel or barrel. The initial fermentation takes place in steel tanks. This process of transferring the wine to different barrels or vessels is known as wine racking. During this process, the wine is prevented from getting oxidized. It is stored in airtight containers, in general in barrels. The choice of the vessel for the secondary fermentation is also left to the choice of the winemaker. Oak barrels impart tannins to the wine.

The carbon dioxide is made to escape into the air resulting in still wine production. In the case of the sparkling winemaking process, the carbon dioxide is trapped inside the wine and the wine is aged in a bottle.

winemaking process aging

Filtration

While the wine is aging in the barrels it is tested for the titration or acidity level, sugar levels, and alcohol percentage. To kill off the bacteria present in the wine, sulfur dioxide is added to the wine. It is added prior to fermentation and after the alcoholic fermentation. The amount of sulfur dioxide should not exceed 30mg/L.

Wine aging plays an important role in the quality of the wine and not all wines are meant for aging. Know more about the aging of the wine and the factors that contribute to the aging of the wine in our wine aging guide.

The aging process generally happens from three to six months. During aging the amino acids in the grapes and the phenolic compounds are allowed to settle and their reaction is controlled and the wine structure becomes smooth.

To proceed to the next step in the winemaking process, bottling, wine has to be clarified.

Clarifying wine involves filtration of the wine from insoluble components like yeast remains, grape skins, and other pieces. The traditional method for wine fining or wine clarifying is the use of gelatine to the wine. Gelatine dissolves tannins and is highly effective in controlling the acidity of the wine. It forms sediment at the bottom and is removed by filtration.

6. Bottling

Bottling the wine is the last step in the winemaking process, where the wine gets its place into the bottle, again sulfur dioxide is added to the bottle to prevent micro bacterial growth and to preserve for a longer period of time against oxidation. Wine is pumped into the bottles from the tanks and the bottles are closed with the corks to prevent oxidation.

winemaking process bottling

What makes a good wine? What makes a wine expensive?

The quality of the wine is decided by many factors from the grapes used in the making to the vinification procedure.The quality of the wine is assessed by the label of the wine.Wine label has lots of information about the grape variety,quality of the wine,its vintage and the bottler information.

In general, wines are classified as table wines and superior wines. Table wines are wines of a low quality that do not meet the requirements or specifications of the quality standards. The higher the quality standard, the higher the price of the bottle. In general, aged and matured wines are expensive compared to younger wines.

Winemaking process flowchart

winemaking process flowchart

“From vineyard to the glass, winemaking process presents before us a long and beautiful journey”

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