What does bacteria do to cheese?

Bacteria are essential for making cheese, playing a critical role in transforming milk into the delicious, diverse range of cheeses we enjoy. Here's how bacteria work their magic:

1. Lactic Acid Fermentation:

* Starter Cultures: Specific types of bacteria, like Lactococcus, Lactobacillus, and Streptococcus, are added to the milk.

* Lactic Acid Production: These bacteria break down lactose (milk sugar) into lactic acid. Lactic acid lowers the pH of the milk, making it acidic.

* Coagulation: The acidic environment causes the milk proteins (casein) to coagulate, forming curds.

2. Flavour Development:

* Enzymes: Bacteria produce enzymes that break down milk proteins and fats, releasing complex flavours and aromas.

* Fat Breakdown: Some bacteria break down fats into short-chain fatty acids, contributing to the buttery, creamy notes in cheese.

* Aroma Compounds: Different bacteria produce different flavour compounds, resulting in the wide range of flavour profiles in cheese.

3. Texture and Consistency:

* Curd Formation: Bacteria play a crucial role in forming the curds, influencing their texture and consistency.

* Ripening: During the aging process, bacteria continue to work, affecting the texture of the cheese. Some bacteria contribute to the development of crumbly textures, while others create smooth and creamy textures.

4. Mold Growth:

* Penicillium: Some cheeses, like blue cheese, rely on mold growth for their unique characteristics. Penicillium molds contribute to the blue veins, pungent aroma, and distinctive flavor of these cheeses.

Examples of Cheese Types and Their Bacteria:

* Cheddar: Lactococcus lactis, Lactobacillus plantarum

* Swiss: Propionibacterium freudenreichii (produces CO2 for holes)

* Blue Cheese: Penicillium roqueforti

* Brie: Penicillium candidum

In summary: Bacteria are essential for cheesemaking. They transform milk into curds, contribute to flavor development, influence texture, and create unique characteristics in different cheese varieties. They are the unsung heroes of cheesemaking, shaping the delicious world of cheese we know and love.