How to make wine from grapes

Wine is defined differently in laws of different countries, e.g., in the United States it is defined as the fermented juice of various fruits. wine generally denotes the product produced by the fermentation of grape juice. The most satisfactory definition seems to be “wine is a beverage resulting from fermentation by yeast of the grape juice with proper processing and addition.”
wine strictly denotes the fermented alcoholic beverage introduced from grape juice without distillation. Grapes have been historically connected with wine-making because of the following advantages:

o Juice is extremely rich in natural sugar.
o Natural association of fermentative yeasts with berries
o High content of nitrogenous matter in promoting the growth of yeasts and enhancing fermentation
o Hich acidity of juice favors yeasts and protects against other bacterial fermentation.
o High alcohol and acid content in the fermented wine keep it stable and safe for prolonged storage.

The varieties of wines are endless and they differ in so many attributes that are difficult to classify. According to color, there are two types, red wine and white wine. In making red wines, the grapes are crushed and stemmed but the skin and seed are left in the must. White wines are made from white or greenish grapes or from the juice of grapes from which the skin has been removed.

Grape’s wine is of two kinds, dry wine and sweet wine. Dry wines are those which contain very little or no sugar that can be detected by testing. In sweet wine, the sugar content is high enough detected by taste. The alcohol content of those kinds of wines ranges from 7 to 20 percent. Wines with 7-9 percent alcohol are known as “Light” those with 9-16 percent “medium”, and those with 16-21 percent “strong”

Sparkling wines contain carbon dioxide. They are made effervescent by secondary fermentation in closed containers, generally in the bottle itself. wines are those that do not contain carbon dioxide. Fortified wines contain added alcohol in the form of brandy. Generally, wines with more than 12 percent alcohol are fortified with fruit brandy (alcohol) prepared by distilling grape wine.

Equipment required in wine-making

1. crushing and pressing: roller crusher or basket press
2. Primary fermentation vessel: open-ended cylindrical vessels of suitable size made of plastic or glass
3. Fermentation vessel: Narrow-mouthed containers of wood, plastic, or glass.

Selection of fruits: The grape berries should be ripe and fresh. Remove blemished white wine is produced from varieties having greenish or yellowish skin. Red wines derive their color from a red pigment present in the skin or flesh of colored varieties of grapes suitable for winemaking below:

o European grape beauty seedless, Arka Shyam
o American grape concord, Catawea, Niagra
o Muscadine grape James, scupper

Crushing: It is done with the help of a basket press. Before crushing the grapes, their stems and stalks are removed. Crushed materials (must) are put in jars which should not be filled more than three-fourths.

Addition of sugar: cane sugar is added to maintain at least 20 percent total soluble solids but not more than 24 percent. If the grapes are sour 70 g of sugar is added for each kg of grapes.

Adjustment of pH: If necessary. pH of the juice has to be adjusted. If it is too low, the juice is diluted with water; if too high, tartaric acid is added to lower it. If water is added more sugar has also been added to raise the percentage of total soluble solids. Usually, an acid content of 0.6-0.8 percent is maintained.

Flow-Sheet How To Make Wine From Grapes

o Ripe grapes
o Remove Stems
o Crushing
o Filling jar up to three-fourths
o Addition of sugar 20-22%
o Adjustment of pH 0.6-0.8% acid
o Addition of preservative (KMS 1.5 g/10 kg)
o Keeping for an hour
o Addition of wine yeast (20 ml/5kg)
o Fermentation 2 days
o Filtration
o Fermentation 10 days
o Racking
o Fining and filtration
o Aging and maturation 6-8 month
o Pasteurization at 80 degrees Celsius for 2 minutes
o Bottling/store at a cool place

Addition of preservative: Potassium metabisulphite (KMS) is added at the rate of 1.5 g for every 10 kg of grapes, mixed, and allowed to stand for 2-4 hours. KMS inhibits the growth of wild yeasts and spoilage organisms.

Addition of wine yeast: Wine yeast, e.g., Saccharomyces ellipsoids inoculum is added at the rate of 20 ml for every 5 kg of grapes, about an hour after the addition of preservatives. If the yeast is not available then potassium metabisulphite is not added. The yeast present in the skin of grapes also ferments and produces wine but is not of good quality.

Fermentation: Grapes are allowed to ferment for two days in a cool place i.e., at 22-28 degrees. The jar mouth is covered with cloth during fermentation.

Filtration: the contents are filtered through a thin muslin cloth or a filter aid on the third day and the filter is again allowed to ferment in a cool place for another ten days without any disturbance. Due to this period, yeast cells and other solids settle at the bottom.

Racking: Syphoning off the fermented wine to separate it from the solid deposits is known as racking.

Filtration and Fining: the newly prepared wine is sometimes not clear and requires fining and filtration. A suitable fining agent, e.g., bentonite, is added. All the colloidal materials settle down along with bentonite. The clear siphoned wine is filtered if necessary. Alternatively, the wine is stored in a refrigerator for about two weeks and thereafter the clear wine is siphoned off.

Aging (Maturation): the clear wine that is siphoned off is filled into bottles or barrels. These should be filled completely and sealed airtight. This wine is allowed to mature 8-6 months in a cool place. Sometimes fermentation continues in the bottle with the result that the cork flies off or the bottle cracks. Wine loses its Flavors during aging because of which barrels of oak wood are generally used for storing it the wood imparts a fine aroma of the wine.

Packing: The volatile acid content of wine (acetic acid), should be low. The high content of volatile acids (0.09-0.20 g/100 ml, in terms of acetic acid) indicates that acetic acid bacteria are active during fermentation. It is often desirable to pasteurize the wine to destroy spoilage organisms and coagulate the collides that cause cloudiness. Generally, wines are pasteurized at 82-88 degrees for 1-2 minutes and then bottled. The bottles are closed with crown crocks of good quality. Pasteurized at 65 degrees for about 20 minutes, then cooled and stored.