Before operating a small yogurt production line , make sure you are familiar with and understand the equipment’s operating manual and safety procedures. This comprehensive step-by-step guide covers the complete operation process, from raw milk reception to finished product packaging, with detailed parameters and safety precautions.
Basic Process of the Small Yogurt Production Line
The basic production process of yogurt follows this sequence:
Raw Milk Storage → Filtration → Preheating → Homogenization → Pasteurization → Cooling → Inoculation → Fermentation → Filling → Cold Storage
Each stage requires specific temperature control, timing, and equipment operation to ensure consistent product quality.
Small Yogurt Production Line Equipment List
A complete small yogurt production line (200-500L daily capacity) includes the following equipment:
| Equipment | Function | Capacity | Key Parameters |
|---|---|---|---|
| Raw Milk Cooling Tank | Storage and cooling | 200-500L | Maintain 4°C |
| Single/Duplex Filter | Remove impurities | 100 mesh | Flow rate: 500-1000L/hr |
| Milk Pump | Transfer milk between stages | 1-3 m³/hr | Food-grade stainless steel |
| Preheating Tank | Warm milk to processing temp | 200-500L | 40-50°C, 20 min |
| Homogenizer | Break down fat globules | 300L/hr | 150-250 bar, 60-70°C |
| Pasteurization Tank | Heat treatment for safety | 200-500L | 85°C, 30 min |
| Fermentation Tank | Culture incubation | 200-500L | 42°C, 6-8 hours |
| Filling Machine | Package yogurt | 500-1000 cups/hr | Automatic or semi-auto |
| CIP Cleaning System | Automated cleaning | Match line | 80-90°C, chemical dosing |
Step-by-Step Yogurt Processing Operation
Step 1: Raw Milk Reception and Storage
Objective: Receive and store fresh milk at proper temperature
Operation Procedure:
- Quality Testing: Test incoming milk for temperature (<10°C), acidity (pH 6.6-6.8), and antibiotic residues
- Transfer to Tank: Use stainless steel milk pump to transfer raw milk to cooling tank
- Cool to 4°C: Activate cooling system to maintain milk at 4°C until processing
- Record Data: Log milk volume, temperature, supplier, and test results
Key Parameters:
| Parameter | Standard | Action if Out of Range |
|---|---|---|
| Temperature | <10°C on arrival | Reject if >10°C |
| Storage Temperature | 4°C | Adjust cooling system |
| pH | 6.6-6.8 | Test for spoilage |
| Antibiotic Test | Negative | Reject milk if positive |
Step 2: Filtration
Objective: Remove impurities and foreign materials from raw milk
Operation Procedure:
- Prepare Filter: Install clean 100-mesh filter element
- Start Pump: Turn on milk pump at low speed
- Monitor Flow: Ensure steady flow through filter
- Check Filter: Inspect filter element after each batch
- Clean/Replace: Clean or replace filter if clogged
Key Parameters:
| Parameter | Standard |
|---|---|
| Filter Mesh Size | 100 mesh (150 μm) |
| Flow Rate | 500-1000L/hr |
| Filter Cleaning | After each batch |
| Filter Replacement | Weekly or when damaged |
Step 3: Preheating
Objective: Warm milk to optimal temperature for homogenization
Operation Procedure:
- Transfer Milk: Pump filtered milk to preheating tank
- Set Temperature: Adjust heating system to 40-50°C
- Hold Time: Maintain temperature for 20 minutes
- Monitor: Check temperature every 5 minutes
- Prepare for Next Stage: Ensure homogenizer is ready
Key Parameters:
| Parameter | Standard | Notes |
|---|---|---|
| Temperature | 40-50°C | Optimal for homogenization |
| Holding Time | 20 min | Ensure even heating |
| Agitation | Continuous | Prevent hot spots |
Step 4: Homogenization
Objective: Break down fat globules for smooth, uniform texture
Operation Procedure:
- Preheat Homogenizer: Ensure milk temperature is 60-70°C
- Set Pressure: Adjust homogenization pressure to 150-250 bar
- Start Machine: Turn on homogenizer at low speed
- Monitor: Check pressure gauge and milk temperature
- Process Batch: Run entire batch through homogenizer (approximately 1 hour for 300L)
- Clean: Flush system with warm water after use
Key Parameters:
| Parameter | Standard | Impact |
|---|---|---|
| Temperature | 60-70°C | Lower temp reduces efficiency |
| Pressure | 150-250 bar | Higher pressure = finer texture |
| Processing Time | ~1 hour for 300L | Depends on capacity |
Step 5: Pasteurization (Sterilization)
Objective: Eliminate pathogenic bacteria while preserving beneficial properties
Operation Procedure:
- Transfer Milk: Pump homogenized milk to pasteurization tank
- Heat to 85°C: Activate heating system (350# heat-conducting oil or hot water)
- Hold Temperature: Maintain 85°C for 30 minutes
- Monitor: Check temperature every 5 minutes
- Record: Log time, temperature, and batch number
- Prepare for Cooling: Ensure cooling system is ready
Key Parameters:
| Parameter | Standard | Notes |
|---|---|---|
| Temperature | 85°C | Standard pasteurization |
| Holding Time | 30 min | For 300L batch |
| Large Batch (>300L) | 40-60 min | Adjust time accordingly |
| Heat Source | Hot water or thermal oil | Depends on equipment |
Step 6: Cooling and Inoculation
Objective: Cool milk to fermentation temperature and add starter culture
Operation Procedure:
- Activate Cooling: Use cold water for pre-cooling (0.3-0.5 hours)
- Cool to 45°C: Monitor temperature until it reaches 42-45°C
- Prepare Culture: Measure starter culture (2-3% of milk volume)
- Add Culture: Sprinkle culture evenly over milk surface
- Gentle Mixing: Agitate slowly for 5-10 minutes to distribute culture
- Seal Tank: Close fermentation tank to prevent contamination
Key Parameters:
| Parameter | Standard | Notes |
|---|---|---|
| Cooling Time | 0.3-0.5 hours | Use cold water |
| Target Temperature | 42-45°C | Optimal for culture |
| Culture Dosage | 2-3% of milk volume | Follow manufacturer instructions |
| Mixing Time | 5-10 min | Gentle agitation |
Step 7: Fermentation
Objective: Allow culture to convert lactose to lactic acid
Operation Procedure:
- Set Temperature: Maintain fermentation tank at 42°C
- Monitor pH: Check pH every hour (target: 4.5-4.6)
- Check Consistency: Observe yogurt texture after 4 hours
- End Fermentation: Stop when pH reaches 4.5-4.6 (typically 6-8 hours)
- Cool Immediately: Reduce temperature to 4-6°C to stop fermentation
- Transfer to Filling: Move fermented yogurt to filling machine
Key Parameters:
| Parameter | Standard | Notes |
|---|---|---|
| Temperature | 42°C | Maintain ±0.5°C |
| Fermentation Time | 6-8 hours | Depends on culture activity |
| Target pH | 4.5-4.6 | Stop fermentation at this point |
| Cooling Temperature | 4-6°C | Prevent over-fermentation |
Step 8: Filling and Packaging
Objective: Package yogurt into containers for distribution
Operation Procedure:
- Prepare Filling Machine: Clean and sanitize all contact surfaces
- Set Fill Volume: Adjust filling machine to target volume (e.g., 200g per cup)
- Load Containers: Place empty cups/bottles on conveyor
- Start Filling: Activate filling machine
- Seal: Apply lids or foil seals immediately after filling
- Label: Apply product labels with date and batch number
- Cold Storage: Transfer filled products to cold room (2-6°C)
Key Parameters:
| Parameter | Standard | Notes |
|---|---|---|
| Fill Volume | Per product spec | ±2% accuracy |
| Filling Temperature | 4-6°C | Maintain cold chain |
| Sealing Temperature | 150-180°C | For heat sealing |
| Storage Temperature | 2-6°C | Until distribution |
Safety Precautions
Personal Safety
| Precaution | Requirement |
|---|---|
| Protective Clothing | Wear clean uniform, hairnet, gloves |
| Hand Washing | Wash hands before handling equipment |
| Footwear | Use sanitized, non-slip footwear |
| Health Check | No open wounds or illness |
Equipment Safety
| Precaution | Requirement |
|---|---|
| Lockout/Tagout | Disconnect power before maintenance |
| Hot Surfaces | Allow equipment to cool before handling |
| Chemical Handling | Wear gloves when handling cleaning chemicals |
| Electrical Safety | Keep water away from electrical panels |
Food Safety
| Parameter | Standard | Action if Out of Range |
|---|---|---|
| Temperature | <10°C on arrival | Reject if >10°C |
| Storage Temperature | 4°C | Adjust cooling system |
| pH | 6.6-6.8 | Test for spoilage |
| Antibiotic Test | Negative | Reject milk if positive |
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Daily Operation Checklist
| Parameter | Standard | Action if Out of Range |
|---|---|---|
| Temperature | <10°C on arrival | Reject if >10°C |
| Storage Temperature | 4°C | Adjust cooling system |
| pH | 6.6-6.8 | Test for spoilage |
| Antibiotic Test | Negative | Reject milk if positive |
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Conclusion
Operating a small yogurt production line requires attention to detail, proper temperature control, and strict hygiene practices. By following this step-by-step guide, you can consistently produce high-quality yogurt while maintaining food safety standards. Regular training, documentation, and preventive maintenance are key to long-term operational success.
Contact Shuliy Machinery for comprehensive operator training programs and technical support for your yogurt production line.
What is the basic process of yogurt production?
The basic process includes: raw milk storage → filtration → preheating → homogenization → pasteurization → cooling → inoculation → fermentation → filling → cold storage. Each stage requires specific temperature control and timing.
How long does it take to make yogurt in a small production line?
A complete production cycle takes approximately 10-14 hours, including 30 minutes for pasteurization, 6-8 hours for fermentation, and 1-2 hours for filling and packaging.
What temperature is needed for yogurt fermentation?
Yogurt fermentation requires a temperature of 42°C (±0.5°C). The fermentation process typically takes 6-8 hours until the pH reaches 4.5-4.6.
How do I clean a yogurt production line?
Use CIP (Clean-in-Place) systems with a standard cleaning cycle: pre-rinse with warm water, caustic wash at 70-80°C, acid wash, and final sanitization. Clean after each production batch.
