Control of wine fermentation process

### Key Points for Controlling Wine Fermentation

#### **1. Alcoholic Fermentation Overview**

- **Primary Process**: Yeasts convert reducing sugars in grape juice into alcohol and carbon dioxide.

- **Byproducts**: Volatile acids, higher alcohols, fatty acids, and esters contribute to the wine's secondary aromas.

- **Control Importance**: Proper fermentation management ensures a balanced composition, enhancing sensory quality.

#### **2. Temperature Control**

- **White Wine Fermentation**:

- Optimal temperature: **14°C to 18°C**.

- Too low: Slows fermentation and increases oxidation.

- Too high: Accelerates fermentation, reducing fruitiness and quality.

- Equipment: Use cooling strips or cold wipes to regulate temperature.

- **Red Wine Fermentation**:

- Optimal temperature: **26°C to 30°C** (minimum 25°C, maximum 32°C).

- Too low: Insufficient tannin and pigment extraction, affecting color and flavor.

- Too high: Damages grape fruitiness and aroma.

- Equipment: Cooling belts or cold wipes are essential for temperature regulation.

#### **3. Monitoring Fermentation**

- **Specific Gravity Measurement**:

- Tracks sugar content and fermentation progress.

- Stop fermentation when sugar levels are near zero.

- Analytical titration confirms residual sugar levels.

- Residual sugar below **0.2 g/L** indicates completion of fermentation.

Proper temperature control and monitoring ensure optimal wine quality by balancing byproduct formation and preserving desired sensory characteristics.