pH value in dairy production: the secret for optimal quality
If you’re wondering what the secret to optimal quality yoghurt, cottage cheese, cheese, or other dairy products is, the answer may surprise you: pH value. Although time is often monitored during the production process, it is actually the control of pH value that plays a crucial role in dairy making. Managing the correct pH value is the key to achieving consistent quality and flavor in your dairy products.
Protecting & preservingRight ingredientsWhat is pH, exactly?
It is a measure of the acidity of a product, measured on a scale from 0 to 14. A pH of 7 is considered neutral, while lower values belong to acidic solutions and higher values are alkaline. In dairy production the pH value of milk and the final product is measured to assess acidity and determine whether the desired acidity level has been achieved.
Why is the pH value so important?
In the production of fermented dairy products (such as yogurt and cheese) lactic acid bacteria play a crucial role in the fermentation process. These bacteria produce lactic acid by breaking down lactose in the milk, which lowers the pH of the milk and promotes the coagulation (clumping together) of milk proteins. Therefore, the pH value is a crucial indicator, as it indicates how the production process is progressing and whether the lactic acid bacteria need more time to produce the perfect final product. The pH should be at the right value by the end of fermentation. However, when this value is reached depends on various factors, such as:
- The freshness of the milk
- Seasonal variations in milk
- Phage influences
Due to these influences, the required fermentation time may vary and therefore it is better to control pH rather than relying on timing. Besides, there are legal guidelines regarding pH values in combination with the naming of the final product; for example, yogurt can only be called so if the pH is lower than 4.5, and buttermilk requires a pH lower than 5.0.
Additional opportunities to control consistency, taste, and shelf life
With cultures, you can not only control the fermentation process but also determine and regulate the texture, taste, and aroma of dairy products. Furthermore, there are specific protective cultures that extend the shelf life of the final product.
Measurement is knowledge, guessing is missing
To measure the pH value in dairy processing we recommend to use a pH meter specifically designed for dairy products. Follow the steps below:
- Ensure that the pH meter is calibrated according to the manufacturer’s instructions, as this is crucial for accurate measurements.
- Take a sample of the dairy product you want to test, such as milk, yogurt, or cheese.
- Stir the sample thoroughly to ensure homogeneity.
- Place the pH electrode of the pH meter in the sample and wait for the measurement to stabilize. This may take a few seconds to minutes, depending on the type of sample and pH meter.
- Read the pH value on the meter’s screen and write it down for documentation.
- Clean the pH meter with clean water and store it according to the manufacturer’s instructions.
If achieving the desired pH value during fermentation takes increasingly more time or varies significantly with each production, it may indicate a phage contamination. In such cases, it is advisable to implement phage rotation. Read more about phage rotation and phage contamination in this article.
Maintaining pH value under control
Regular monitoring by using a pH meter provides reliability and consistency in dairy processing. As always: relying on intuition or time management can be helpful, but better is a good pH measurement.
Do you want to learn more about controlling the right pH value and cultures?
