Are cheeses acidic or alkaline? The pH of dairy explained

January 6, 2026 •

2 min read

Milk, the primary ingredient for cheese, begins with a pH of about 6.6–6.7. While this is close to neutral, almost all cheeses undergo a process that makes them acidic, with the final pH influenced by their specific type and aging process.

Quick Summary

Cheese is primarily an acidic food, a result of the lactic acid produced by bacteria during fermentation. The specific pH level, which varies significantly between cheese types, profoundly influences its final flavor, texture, and moisture content.

Key Points

Primarily Acidic: Most cheeses are acidic due to the lactic acid produced by bacteria during fermentation.
pH Varies by Type: Different cheeses have varying pH ranges; for instance, fresh cheeses like feta are more acidic (lower pH) than aged blue cheeses.
Texture and Flavor are Linked to pH: Cheeses with a lower pH are sharper and firmer, while those with a higher pH are milder and softer.
Aging Can Increase pH: In some soft and blue cheeses, the pH rises during ripening as molds or bacteria metabolize lactic acid.
Cheesemakers Control Acidity: The choice of starter culture, moisture level, and aging process are all tools cheesemakers use to control a cheese's final pH.

The Science Behind Cheese pH

At its core, the acidity of cheese is a product of fermentation. In the cheesemaking process, starter cultures—beneficial bacteria—are added to milk. These cultures ferment lactose, the natural sugar in milk, converting it into lactic acid. This process lowers the milk's pH and causes proteins to coagulate, forming the curds for cheese.

The Role of Lactic Acid Fermentation

As bacteria convert lactose to lactic acid, the pH decreases. This pH change impacts the cheese's final characteristics, affecting texture and flavor. The acidic environment also helps prevent the growth of undesirable bacteria.

How pH Shapes Cheese Texture and Flavor

The pH level directly impacts cheese texture. Calcium in milk binds proteins, and as acidity increases, lactic acid releases calcium ions, altering the protein structure. This leads to:

Higher pH (less acidic): Softer, more elastic textures, like in fresh mozzarella or some Swiss cheeses.
Lower pH (more acidic): Firmer, more crumbly textures and sharper, tangier flavors, characteristic of aged cheddar.

Acidity Levels Across Different Cheese Types

While cheesemaking starts with an acidic process, the final pH of cheeses varies widely depending on the type and aging.

What Makes Some Cheeses Less Acidic?

During ripening, some cheeses, such as Brie, Camembert, and blue cheeses, become less acidic. Molds or surface bacteria on these cheeses metabolize lactic acid, producing alkaline compounds that raise the pH towards neutral or slightly alkaline levels. This buffering process contributes to their soft rinds and creamy textures.

Factors Influencing a Cheese's Final Acidity

Factors like the type of starter culture, moisture content, aging conditions, and manufacturing techniques like washing curds all influence a cheese's final acidity. For more detailed information on controlling acidity and moisture in cheesemaking, visit the {Link: Center for Dairy Research https://www.cdr.wisc.edu/controlling-acidity-moisture}.

Acidity Comparison: Cheese Types and pH

Different types of cheese have varying pH ranges affecting their characteristics. Fresh cheeses typically have a high acidic pH (4.6–4.9) resulting in a tangy flavor, while semi-hard (5.1–5.4) and hard cheeses (5.2–5.8) are medium acidic. Soft-ripened and blue cheeses tend to approach a more neutral or alkaline pH (6.0–7.0) as they age.

Conclusion: It's Mostly Acidic, but with Variations

Most cheeses are acidic due to lactic acid production during cheesemaking. However, pH varies greatly by type. Some aged cheeses become less acidic during ripening due to mold or bacterial action. The alkaline diet classifies all dairy as acid-forming metabolically, separate from intrinsic pH.

Key Takeaways

Primarily Acidic: Most cheeses are acidic due to lactic acid from bacterial fermentation.
pH Varies by Type: Cheeses like fresh feta are more acidic than aged blue cheeses.
Texture and Flavor Link: Lower pH means sharper and firmer; higher pH means milder and softer.
Aging Can Raise pH: Some cheeses see pH rise during ripening as molds break down lactic acid.
Cheesemakers Control Acidity: Starter culture, moisture, and aging are used to control final pH.

Frequently Asked Questions

While almost all cheese is acidic during its initial creation, some ripened cheeses, like Brie, Camembert, and certain blue cheeses, have their pH rise during aging and can approach a more neutral or slightly alkaline state.

Cheese is acidic because cheesemakers add starter cultures of bacteria to milk. These bacteria ferment the lactose (milk sugar), converting it into lactic acid, which lowers the overall pH.

Milk typically starts with a pH of about 6.6 to 6.7, which is very close to neutral on the pH scale. The cheesemaking process then intentionally lowers this pH.

Yes, pH significantly affects flavor. A lower, more acidic pH often results in a sharper, tangier taste, while a higher pH (closer to neutral) typically produces a milder, buttery flavor.

In many aged cheeses, especially soft-ripened and blue varieties, the pH initially drops but then increases over time due to the activity of molds or surface bacteria that break down lactic acid.

Yes, cheddar cheese is acidic. It typically has a pH range of 5.1 to 5.4, and its characteristic sharp flavor is directly linked to this acidity level.

The alkaline diet classifies all dairy products, including cheese, as 'acid-forming,' meaning it promotes acid production in the body after digestion. This is a different concept from a food's intrinsic pH and the diet recommends avoiding it.