The production of cheese is a fascinating blend of art and science, and at its heart lies the use of cultured bacteria. A cheese culture is a carefully selected group of bacterial strains, primarily lactic acid bacteria, added to milk at the beginning of the cheesemaking process. These 'starter cultures' consume the lactose (milk sugar) and convert it into lactic acid, a process known as fermentation. This acidification is fundamental, serving several critical functions: it helps coagulate the milk, acts as a natural preservative by inhibiting harmful bacteria, and lays the groundwork for the cheese's final flavor and texture during aging.
The Two Main Types of Cheese Cultures
Most cheese cultures can be categorized into two main types based on the temperatures at which they thrive: mesophilic and thermophilic. The choice of culture is a primary determinant of a cheese's final characteristics.
Mesophilic Cultures
Mesophilic cultures work best at moderate temperatures, typically between 68°F and 102°F (20°C and 39°C). They are the most common type of culture and are responsible for a wide range of popular cheeses. The bacteria in these cultures, such as Lactococcus lactis, produce lactic acid at a slower rate than their thermophilic counterparts, which contributes to the complex flavor development in many traditional varieties.
Examples of cheeses made with mesophilic cultures include:
- Cheddar
- Gouda
- Colby
- Monterey Jack
- Feta
- Brie and Camembert (often with additional molds)
Thermophilic Cultures
Thermophilic cultures, or 'heat-loving' bacteria, are used for cheeses that require higher temperatures during the cheesemaking process, with optimal temperatures ranging from 108°F to 128°F (42°C and 53°C). These cultures, including strains like Streptococcus thermophilus and Lactobacillus bulgaricus, are essential for producing the distinctive flavors and often firmer texture of Italian and Swiss-style cheeses.
Cheeses made with thermophilic cultures include:
- Mozzarella
- Parmesan
- Provolone
- Swiss
- Romano
Uncultured vs. Cultured Cheese: A Matter of Method
Not all cheeses are cultured. The primary distinction lies in how the milk is coagulated. While cultured cheeses use beneficial bacteria to ferment the milk and aid coagulation, uncultured cheeses rely on a direct acid or enzyme addition.
- Cultured Cheese: The majority of aged and ripened cheeses, from the softest Brie to the hardest Parmesan, use starter cultures to develop their signature characteristics. The fermentation process is central to their flavor profile and texture.
- Uncultured Cheese: Some fresh cheeses are made by adding an acid, such as citric acid or vinegar, directly to heated milk to curdle it. This bypasses the fermentation step, resulting in a different flavor and texture. Examples include paneer and some forms of ricotta.
The Role of Adjunct and Mold Cultures
While mesophilic and thermophilic bacteria are the most common workhorses, some cheeses require additional cultures for specific effects.
- Mold Cultures: Cheeses like Brie and Camembert require the white mold Penicillium camemberti to ripen their surface and create their characteristic soft rinds. Blue cheeses, such as Roquefort and Stilton, are ripened with the internal mold Penicillium roqueforti.
- Propioni bacteria: These special bacteria are responsible for the distinctive 'eyes' or holes in Swiss cheese, as well as its nutty flavor.
- Surface-Ripening Bacteria: Cheeses with washed rinds, such as Limburger and Munster, owe their pungent aroma and reddish-orange color to bacteria like Brevibacterium linens.
Comparison of Cultured Cheese Types
| Characteristic | Mesophilic Cultures | Thermophilic Cultures |
|---|---|---|
| Optimal Temperature | 68–102°F (20–39°C) | 108–128°F (42–53°C) |
| Flavor Profile | Mild to sharp, often with buttery notes | Complex, nutty, and sometimes sweeter |
| Texture | Varies widely, from soft (Brie) to hard (Cheddar) | Often firmer and more compact (Mozzarella, Parmesan) |
| Cheese Examples | Cheddar, Gouda, Feta, Brie, Colby, Monterey Jack | Mozzarella, Parmesan, Swiss, Provolone, Romano |
| Common Bacteria | Lactococcus lactis, Lactococcus cremoris | Streptococcus thermophilus, Lactobacillus bulgaricus |
What are cultured cheese benefits?
The process of culturing milk to make cheese offers several benefits beyond just taste and texture, including potential health advantages. Fermentation creates probiotics, which can support digestive health. For individuals with lactose intolerance, the fermentation process breaks down much of the lactose, making cultured cheeses often easier to digest than unfermented dairy products. The presence of beneficial bacteria also aids in the absorption of key nutrients.
Conclusion
Whether you're enjoying a pungent blue cheese, a sharp aged cheddar, or a fresh, creamy mozzarella, the rich and complex flavors are almost certainly the product of specific bacterial cultures. The intentional introduction and careful management of mesophilic, thermophilic, or specialty cultures is the reason for the incredible diversity in the world of cheese. From altering the texture and flavor to acting as a natural preservative, these tiny microorganisms are the unsung heroes of cheesemaking. The decision to use a specific culture, or a combination of them, is what transforms simple milk into a vast array of cultured cheeses enjoyed around the globe.
