How to Use pH Measurements for Cheese Making

Cheese making is an artisan craft that can be a beloved hobby, a business, or both. With hundreds of varieties of cheese around the world, recipes and possibilities are endless. Skilled cheese makers refine each step in the process to achieve consistent and delicious results.

The Cheese Making Process

The cheese making process begins with the addition of microorganisms, referred to as “starter cultures,” to a dairy product such as milk. The bacteria in the starter cultures consume the sugar (lactose) in the milk and produce a byproduct (lactic acid) during a process called fermentation.

Lactic acid production begins the process of coagulation, by which the starting liquid begins to solidify. Cheese makers often aid and expedite this process through the addition of the enzyme rennet to the fermenting mixture. When coagulation has produced the ideal mixture consistency, the process continues with cutting. Cutting is a mechanical process that encourages the solid element (curds)—which ultimately become the cheese—to separate from the liquid (whey). After cutting, the mixture is cooked and stirred, causing additional expulsion of whey from the curds.

At this point, salt is often added to promote whey expulsion, improve taste, and preserve the final product. Finally, the cheese is pressed to remove remaining whey. The product may then be consumed fresh or placed in a controlled environment for aging or “ripening.”

The Role of pH in Cheese Making

To properly execute the cheese making process and achieve the desired flavor and texture of the product, it can be useful to monitor temperature and pH. These measurements provide insight into the cheese making process, informing the cheese maker on how to adjust for optimal results. For example, cheese makers adjust the temperature of the milk and the type and amount of starter culture added to control the amount of lactic acid produced by fermentation. This helps guarantee that the desired taste and texture of cheese is produced. Measuring pH allows cheese makers to monitor lactic acid levels, because lactic acid decreases the pH of the mixture.

Many cheese recipes advise proceeding to a subsequent process step, such as cutting, only when a certain pH level is reached. Most cheese making processes occur at a pH between 5.1 and 5.9, which is slightly acidic according to the pH scale, which ranges from 0-14. Monitoring pH provides the information necessary to properly follow more advanced recipes, or to ensure that your own favorite cheeses come out perfect every time.

Do you have experience using pH measurements for cheese making? Tell us about it in the comments!