Why is lactic acid significant in dairy?

Lactic acid plays a crucial role in the dairy industry, particularly in the process of fermentation and the production of various dairy products. When milk is fermented by lactic acid bacteria, these microorganisms convert lactose, the sugar found in milk, into lactic acid. This increase in lactic acid lowers the pH of the milk, which is significant because it causes the proteins in milk, particularly casein, to coagulate or curdle. This curdling is essential for the production of cheese and yogurt, as it forms the solid curds while the liquid whey is separated.

In addition to its role in curdling milk, lactic acid also contributes to the texture and stability of dairy products. It helps to create the desirable consistency of yogurt and influences the ripening and flavor development in cheese. By lowering the pH, lactic acid also acts as a preservative, inhibiting spoilage organisms and extending the shelf life of dairy products.

While lactic acid does enhance milk flavor and is indeed a byproduct of fermentation, its most critical function in dairy is its contribution to curdling, which is the foundational process for many dairy products. This curdling is what sets the stage for further processing and the development of