Production process of original yogurt

### Technical Requirements for Original Flavor Yogurt Production

#### **Process Overview**

1. **Raw Milk Inspection**: Follow "Fresh Milk Quality Standards and Inspection Methods."

2. **Milk Collection**: Collect at ≤8°C.

3. **Filtration**: Use a double filter to remove impurities.

4. **Purification and Cooling**:

- Remove mechanical impurities.

- Cool milk to ≤5°C using a cold plate and store at ≤5°C for up to 12 hours.

5. **Pasteurization**:

- **Preheating**: Heat exchange between hot and cold milk.

- **Pasteurization**: Heat to 85°C ± 5°C for 15 seconds.

- **Cooling**: Cool to ≤8°C.

6. **Ingredients**:

- Mix stabilizers, sugar, and other additives under controlled conditions.

- Ensure uniform mixing and acid adjustment before adding to milk.

7. **High-Temperature Sterilization**:

- **Vacuum Degassing**: Remove air bubbles.

- **Homogenization**: Heat to 70–80°C at 250 bar pressure.

- **UHT Sterilization**: Heat to 120–123°C for 4 seconds.

- **Cooling**: Reduce to ≤25°C.

8. **Aseptic Filling**:

- Maintain sterilization temperatures (e.g., 270°C pre-sterilization, 120–135°C during production).

- Ensure proper sealing and straw application.

9. **Packaging and Testing**:

- Package products and conduct thermal insulation tests at 30–35°C for 120 hours.

- Perform commercial sterility tests before shipment.

#### **Key Technical Requirements**

- **Raw Milk Quality**: Adhere to quality standards and use milk within 12 hours of collection.

- **Temperature Control**: Maintain strict temperature ranges during preheating, pasteurization, and cooling to ensure product quality.

- **Acid Adjustment**: Ensure uniform acid addition to prevent protein flaking and maintain consistency.

- **Sterility Testing**: Confirm product safety through thermal insulation and commercial sterility tests before release.

This process ensures high-quality, safe, and shelf-stable yogurt production.