Making Grape Wine
Clean all utensils thoroughly and rinse them with boiling water before use. Wooden barrels, if used for storing wine should be free from musty or vinegary odors caused by bacteria and molds. Sterilize them by soaking for 24 hours with a solution prepared by dissolving one tablespoon of potassium meta-bisulfite in five gallons of water. If there is not an available supply of potassium meta-bisulfite, a solution of bicarbonate of soda and water will serve nearly the same purpose.
a glass of polyethylene carboy is ideal for fermentation. The narrow neck of the carboy permits the use of a fermentation-lock stopper, which does not allow air or fruit flies to enter the carboy.
When all the fruit has been thoroughly crushed, or the juice extracted, add 1/8 teaspoon of potassium meta-bisulfite to each gallon of juice. Stir the mixture well and let it stand at room temperature for at least 24 hours. This procedure sterilizes the juice by removing wild yeast, molds and bacteria, which if present, may cause an undesirable vinegary or musty flavor. It also helps to preserve the color and clarity of the wine.
Randall-Standish Vineyards adds the potassium meta-bisulfite for you.
Yeast And Fermentation
Pure cultures of wine yeast in the form of packaged dry yeast, or tubed agar cultures may be bought at stores that specialize in wine producers supplies. They are selected yeast strains, capable of growing in the presence of sulfur dioxide, able to produce high concentrations of alcohol, and giving a clean flavored wine. Their use minimizes the risk of having the wine spoiled by the formation of vinegar.
For making five to ten gallons of wine, sprinkle one package of dry yeast over the surface of the must, (Crushed grapes or juice) and when islands of bubbles appear, stir the mixture and allow it to ferment at 65-75ºF. Montrachet yeast is available at our press house.
When making more than ten gallons of wine in one batch, it is best to prepare a starter. To do this, make a small batch of wine from the packaged dry yeast. After 4 hours, when this small batch is fermenting strongly, add it to the main lot of must. Use the starter in the proportion of not less than one gallon to twenty-five gallons of must.
Addition of Sugar
The amount of alcohol and sweetness in the finished wine depends on the amount of sugar in the juice. If grapes are low in sugar, extra sugar may be added before fermentation. The total sugar content, including the natural sugar present in the grapes, should be no more than 24%. If more than this amount is present, the wine will have a harsh flavor because of too much alcohol. Two parts of sugar usually produces one part of alcohol and one part of carbon dioxide, A sugar content of 24% therefore produces 11 - 12 percent alcohol in a completely fermented wine. For lighter alcohol wines adjust the sugar content between 21-22%.
When adding sugar, calculate the total amount needed, usually 1/2 to one pound of sugar per gallon of juice, and divide it into four parts. When fermentation of the natural sugar in the fruit is nearly complete, add the first quarter. Add the second quarter when fermentation again slows down and so on until all of the sugar has been added. This method gives good fermentation and there is no risk of the final wine being too sweet.
Because some grapes are high in acid the juice should be diluted with water before fermenting. In general, if the juice is below 1.0% acid one could add water to equal up to 20% of the total volume, if the acid is above 1% one may add water up to 30%. At the higher water levels it is advisable to add yeast nutrients. They are available from wine equipment suppliers, and usually come in powdered form with directions for their use. If they are not available, one teaspoonful of malt abstract added to each gallon of juice are a good source of yeast nutrients.
If one does not add water, there should be an addition of sugar to bring the total sugar up to the 22-24% level prior to fermentation. Usually two pounds of sugar per gallon of water is sufficient.
Racking And Fining The Wine
When the production of gas slows down and finally stops, sediment begins to settle on the bottom of the carboy. Unlike other fruits, grapes contain a high proportion of tartaric acid, which gives the harsh flavor to new wine. The sediment consists of yeast cells and tartrates, or wine stone.
Shortly after the fermentation stops, rack the wine by siphoning it carefully off the sediment into a clean carboy or glass jug. Always keep the containers filled to the neck. To speed up the removal of tartrates, the wine may be chilled almost to the freezing point after fermentation is complete. Repeat the racking procedure at intervals until no more sediment forms. Racking also incorporates a small amount of air, which helps to hasten the aging process. Add 1/4 teaspoon of meta-bisulfite or one campden tablet to each two gallons of wine after first racking.
Sometimes too much tannin in the wine causes a cloudiness that does not settle out. If this occurs, fining is necessary. Gelatin is the most convenient material to use for fining. Dissolve two teaspoonfuls of powdered gelatin into ten ounces of warm water. If 1/2 ounce of this solution is added to each gallon of wine, more sediment will be deposited. This sediment, in turn, is removed by racking. An even simpler method of fining the wine involves the use of bentonite. This material, added at the rate of 0.1% or one teaspoon per gallon, clears the wine very quickly. It should be well mixed with a small quantity of water and stirred into the wine. The settled sediment is removed by racking after four or five days.
The wine should be brilliantly clear after these treatments, and it is then ready for bottling. If it is too dry for the individual taste, sweeten it by adding sufficient amounts of sugar. If sugar is added, one should add a preservative to prevent the possibility of further fermentation. Sorbistat (Potassium Sorbate) added at the rate of 1/2 teaspoon per gallon of wine will provide adequate protection. To avoid the possibility of your wine oxidizing in the bottle, we tablet to each four gallons of wine before bottling. Fill the bottles to the neck and store them in a cool place. Bottles with cork stoppers should be placed on their sides to prevent the corks from drying out.
Aging And Bottling
Wine may be stored in wooden barrels to age, but this is not essential if chilling and fining have been properly carried out after fermentation. If a barrel is used, make sure it is clean and has no musty or vinegary odor. Barrels that have been used for brandy, whiskey, rum or wine may be used for aging.
Wines mature in the bottles, but more slowly than in a barrel. If a heavy deposit forms on standing, transfer the wine into clean bottles, pouring carefully to avoid disturbing the sedinment. This treatment adds small amounts of air which help to smooth a harsh flavored wine. Bottles should not be partly filled because this causes loss of color and sometimes spoilage; they should be filled to the neck and stored in a cool place.
Questions? Ask The Wine Doctor, John
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