Factory yogurt production involves several key steps, from preparing the milk to packaging the final product. Here's a breakdown of the process:
1. Preparation and Mixing
- Equipment: Large mixing vats or blending tanks are essential.
- Adjust Milk Composition: The fat and solids content of the milk are adjusted. Often, skimmed milk powder is added to increase the total solids, which improves the yogurt's texture and consistency.
- Blend Ingredients: Other ingredients, such as sugar, stabilizers, and fruit purees (for flavored yogurts), are added and thoroughly blended.
2. Pasteurization
- The milk mixture is pasteurized to kill any harmful bacteria. This typically involves heating the milk to a specific temperature for a set amount of time (e.g., 85°C for 30 minutes).
3. Homogenization
- Homogenization forces the milk through a small space at high pressure. This reduces the size of the fat globules, preventing them from separating and creating a more stable and creamy texture.
4. Cooling
- The pasteurized and homogenized milk is then cooled to the optimal temperature for the starter cultures to thrive, generally around 40-45°C (104-113°F).
5. Inoculation
- Adding Starter Cultures: The cooled milk is inoculated with specific starter cultures, typically Streptococcus thermophilus and Lactobacillus bulgaricus. These bacteria ferment the lactose (milk sugar), producing lactic acid, which gives yogurt its characteristic tart flavor and thick texture.
6. Incubation (Holding)
- Controlled Fermentation: The inoculated milk is held at a constant temperature (around 40-45°C) in incubation tanks to allow the starter cultures to ferment the milk. This process usually takes several hours. The duration depends on the desired acidity and consistency of the yogurt.
7. Cooling and Further Processing
- Stopping Fermentation: Once the desired acidity is reached, the yogurt is cooled rapidly to stop the fermentation process.
- Flavoring and Packaging: After cooling, fruit purees, flavorings, or other additives can be mixed in. The yogurt is then packaged into containers.
8. Quality Control
- Throughout the entire process, strict quality control measures are implemented to ensure consistent quality, safety, and adherence to standards. This includes regular testing for bacteria, acidity, and other parameters.
In summary, factory yogurt production involves preparing and blending ingredients, pasteurizing and homogenizing the milk, cooling and inoculating with starter cultures, incubating, cooling again, and finally, flavoring and packaging the finished product. Strict quality control measures are in place throughout the entire process.
