Red Wine Vinification
Red Wine Vinification
Yeast is categorized into two types: natural yeast and artificially cultured yeast. Natural yeasts are wild yeasts that are often attached to the fruit skin. Fruit juice is fermented by the yeast to produce alcohol from glucose and carbon dioxide. After the current fermentation, the wine is filtered, the temperature is controlled, and a post-fermentation process is carried out to further improve the quality and flavor of the wine.
Operation method
fermentation
Principle
Yeast is categorized into two types: natural yeast and artificially cultured yeast. Natural yeasts are wild yeasts that are often attached to the fruit skin. Fruit juice is fermented by the yeast to produce alcohol from glucose and carbon dioxide. After the current fermentation, the wine is filtered, the temperature is controlled, and a post-fermentation process is carried out to further improve the quality and flavor of the wine. In order to ensure the purity of the yeast fermentation and to prevent or inhibit the activity of other stray bacteria, it is necessary to treat the juice with sulfur dioxide. Sulfur dioxide can inhibit the activity of most of the stray bacteria, but does not affect the activity of normal yeast, it has the effect of sterilizing, clarifying, antioxidant, solubilizing and acidifying the fruit wine juice.
Materials and Instruments
Fresh grapes Kiwi Move I. Materials and equipment For more product details, please visit Aladdin Scientific website.
Sucrose Sulfite Dry yeast
Triangular flasks Ceramic plates Straws Corner spoons Glass rods Scales Brix meter Suction balls Gauze Beakers Measuring cylinders Water baths Balances Test strips
Ceramic plate, 250 ml triangular vials (4 per group), 1 ml pipettes, angled spoons, glass rods, bench scale, brix meter, pipette balls, 2 layers of gauze, fresh grapes, kiwi fruit, sulfite (6%, 1% 500 mL), fruit wine-activated dry yeast, sucrose, test strips (pH 3.5), scales, 100 ml beakers, 100 ml measuring jugs, and a water bath.
II. Methodology
1. Cleaning of utensils: Swish beakers, glass rods, triangular flasks and all other utensils that may come into contact with the expected wine during the experiment with 1% sulphurous acid to sterilize them, and wait until the sulphurous acid evaporates before using them.
2. Selection: Grapes (select fully ripe, brightly colored, disease- and mold-free fruits as raw material, remove impurities and rinse the surface clean of soil).
3. Crushing: Remove stems, wash in water and cool dry. Squeeze the fruit, 1 bottle per treatment, 0.4 pounds of grapes per bottle, measure brix, measure pH.
4. Sugar mixing; first determine the sugar content of the fruit pulp, according to the proportion of 18% sugar needed to generate 10% alcohol, add sucrose (18%-25%) that can produce about 10% alcohol, stir to dissolve.
5. Sulfur dioxide treatment: the addition of sulfur dioxide is often added at the time of crushing or juice into the tank before fermentation, so that the sterilization effect is better.Generally commonly used 6% sulfurous acid H2SO3 to obtain SO2, the general dosage is 2.5 ml of sulfurous acid added per liter of juice.
6. Activated dry yeast activation: according to the dosage of 1 g dry yeast / L juice, weigh the active dry yeast, add 10% of the active dry yeast in 40 ℃ warm water, static rehydration activation, 8 min gently stirring once, activation of 20 min, add to the treatment of grape juice.
7. Main fermentation: put the blended pulp into containers, covered with two layers of gauze (to prevent bottle bursting and insects). 25 ℃ fermentation, daily stirring of fermentation material, when the residual sugar drops to about 5% of the end of the main fermentation (fermentation for 7 days). Filter through two layers of gauze to remove the skins and dregs.
8. Finishing: storage at 15°C to allow the wine to mature, which takes about 4 days.
9. Blending sweet wine: Blend 120 g/L sugar sweet wine, according to the sugar content of the original wine and the sugar content to be blended, weigh the corresponding sucrose and mix well.