Bacteria Strains and Functions - Cheat Sheet

Cheesemaking relies on specific bacterial strains to ferment milk, develop flavors, and contribute to the texture of the final product. Here are the most common bacterial strains used in cheesemaking:

Starter Cultures:

These are the primary bacteria used to ferment lactose (milk sugar) into lactic acid, which helps coagulate milk and develop cheese structure.

1. Lactococcus Species (Mesophilic cultures)
   • Lactococcus lactis subsp. lactis
   • Lactococcus lactis subsp. cremoris
   • Used for: Cheddar, Gouda, and other semi-hard and soft cheeses.

   • Function: Acid production in moderate temperatures (20–30°C).

     Streptococcus thermophilus (Thermophilic culture)

   • Used for: Parmesan, Mozzarella, and other high-temperature cheeses.
   • Function: Works at higher temperatures (45°C), producing acid and aiding texture.

Secondary Cultures:

These bacteria influence flavor, texture, and ripening.

1. Lactobacillus Species (Thermophilic cultures)
   • Lactobacillus helveticus
   • Lactobacillus delbrueckii subsp. bulgaricus
   • Lactobacillus casei
   • Used for: Swiss cheese, Parmesan, and aged cheeses.

   • Function: Flavor enhancement, proteolysis, and secondary fermentation.

     Leuconostoc Species

   • Leuconostoc mesenteroides
   • Used for: Gouda and Edam.
   • Function: Produces carbon dioxide and diacetyl, contributing to texture (eye formation) and buttery flavors.

Ripening and Specialty Cultures:

These are added to create distinct flavors, textures, or visual characteristics in specific cheese types.

1. Propionibacterium freudenreichii
   • Used for: Swiss and Emmental cheeses.

   • Function: Produces carbon dioxide (eye formation) and nutty flavors.

     Penicillium Species (Fungi but work alongside bacteria)

   • Penicillium roqueforti: Used for blue cheeses like Roquefort.

   • Penicillium camemberti: Used for surface-ripened cheeses like Brie and Camembert.

     Brevibacterium linens

   • Used for: Washed-rind cheeses like Limburger and Munster.
   • Function: Produces strong aromas and reddish-orange rind.

Non-Starter Lactic Acid Bacteria (NSLAB):

• These occur naturally in milk or develop during aging.
• Species: Lactobacillus plantarum, Lactobacillus brevis, etc.
• Function: Contribute to flavor and complexity during aging.

Here are some simplified and easily digestible explanations for the bacteria strains found in common starter culture mixtures. Once you have become comfortable with the making process, you can begin to pick and choose which bacteria strains you would like to introduce to your cheese, for fine tuned results!

Mesophilic

• Lactococcus lactis subsp. Lactis - Used for acid development
• Lactococcus lactis subsp. Cremoris - Used for acid development, requires more attention to temperature
• Lactococcus lactis subsp. Lactis Biovar Diacetylactis - Used for some acid development, produces gas (CO2) and buttery flavor (diacetyl), faster working
• Leuconostoc mesenteroides subsp. Cremoris - Used for some acid development, produces gas (CO2) and buttery flavor (diacetyl)

Thermophilic

• Streptococcus thermophilus - Used for quick, primary acid development. Survives high heat, but works during aging at lower temperature
• Lactobacillus helveticus - Used for acid development. Survives high heat, while working and developing acid as it cools
• Lactobacillus delbrueckii subsp. Lactis - Used for acid development. Survives high heat, while working and developing acid as it cools as it cools.
• Lactobacillus delbrueckii subsp. Bulgaricus - Used for acid development. Survives high heat, while working and developing acid as it cools as it cools.