ASM Microbes After Hours: The Microbiology of Cheese

Introduction

• Host: Shannon Green, American Academy of Microbiology Colloquium Fellow
• Event: Microbes After Hours by the American Society for Microbiology (ASM)
• Topic: The microbiology of cheese, focusing on microbes' role in cheese production
• ASM Overview:
  • Society with over 100 years of history and nearly 40,000 members
  • Produces FAQ reports on topics like influenza, human microbiome, brewing, and cheese microbiology
• Importance of Microbes:
  • Vital to Earth's life for over 4 billion years
  • Essential in beer and cheese production

Speaker 1: Matteo Keeler

• Background: Co-founder of Jasper Hill Farm; established cheese ripening facilities
• Cheese Making Process:
  • Begins with cow's diet (grass-fed)
  • Cows digest feed with the help of microbes in the rumen
  • Milk is composed primarily of water, casein, fat, lactose, and minerals

Key Elements of Cheese Production

• Microbial Ecology: Sources include cow's udder, environment, and milking equipment
• Cheese Types:
  • Pasteurized vs raw milk cheeses
  • Lactic acid bacteria for acidification
  • Enzyme addition for coagulation

Cheese Ripening Process

• Environmental Control: Air speed, gas pressure, temperature
• Tools for Ripening: Selection of microbial communities, air quality control
• Challenges: Balancing microbial communities for optimal cheese flavor

Speaker 2: Rachel Dutton

• Background: Research group at Harvard focused on microbial ecosystems in cheese
• Microbial Communities: Cheese rinds as biofilms with diverse microbial life
• Research Focus:
  • Understand microbial interactions within cheese ecosystems
  • Use cheese as a model to study complex microbial communities

Microbial Diversity

• Cheese Rind Microbes:
  • Yeasts, molds, bacteria
  • Influence cheese flavor and aroma
• Examples of Microbes:
  • Geotrichum candidum, Penicillium camemberti, Brevibacterium linens

Flavor and Aroma Compounds

• Production by Microbes: Enzymes secreted by microbes break down proteins and fats
• Examples: Methionel (roasting meat flavor), butyric acid (sweaty socks aroma)

Q&A Highlights

• Reproducibility in Cheese Making: Driven by controlled conditions such as pH, salt, moisture, temperature
• Health Aspects: Potential benefits and risks of consuming cheese rinds
• Regulatory Concerns: FDA regulations on traditional cheese-making techniques

Conclusion

• Cheese as a Discovery: The ongoing learning process in cheese microbiology
• Industry Concerns: Regulatory challenges affecting artisan cheese production
• Future Events: Continuation of educational series by the ASM with upcoming topics

Additional Information

• ASM Press on Cheese Microbes: New textbook available on the microbiology of cheese
• Special Tasting: Jasper Hill Farm cheese samples available for participants