Biology 560 - Interdisciplinary Explorations In Biology
Fall, 2011
The Microbiology of Beer, Bread and Cheese

Dr. Tammy Tobin


"God made yeast, as well as dough, and he loves fermentation just as dearly as he loves vegetation."
~Ralph Waldo Emerson

The goal of this course is to introduce you to the fundamental concepts and techniques of fermentation through a variety of disciplines. Gaining a complete understanding of the microbiology of beer, bread and cheese requires that you investigate not only their basic biological and chemical components, but also the amazing metabolic processes performed by the microbes that produce them. We will also explore the incredible ways in which fermentation has shaped (and been shaped by) human history, politics and religion. Ultimately, I hope that this course will help you savor the results of fermentation even more than you already do.

Prerequisites: Must have completed BIOL 101 or 102 AND have 2nd year standing or permission of instructor.  2 SH. 2 lecture hours. CC: Interdisciplinary

Spring 2011 Class at Penn Cheese Corporation

class photo 2011


After taking this course, students will be able to:

1. Demonstrate knowledge of the basic concepts and vocabularies central to:

a) The biology, chemistry and history of fermentation;
b) The scientific basis for the techniques and tools employed in the production of beer, bread and cheese;
c) The roles that different microbial species play in the production of beer, bread and cheese.

2.  Use multiple disciplines, including biology, chemistry, religion, history, poitical science, nutrition, and ecology and to explore and analyze the basics of fermentation science, as detailed above, and to explore the ways in which fermenation has shaped, and continues to shape human society.

3.  Articulate an understanding of the ways in which these disciplines can be brought together not only to supplement and reinforce each other, but also to highlight the complexities and ambiguities inherent to explaining issues central to the science and history of fermentation.

4. Perform biological and chemical tests to assay the results of microbial fermentations.



The final grade will be a composite of your performance in 3 Unit Exams (25% each), two fermentation worksheets (5% each), and one final fermentation essay (15%).

Your final grades will be based on the scale below:

A 94-100%
A- 90-93
B+ 87-89
B 84-86
B- 80-83
C+ 77-79
C 74-76
C- 70-73
D+ 67-69
D 64-66
D- 60-63
F All those numbers below 60


Attendance is required at all scheduled exams and lab sessions. You will receive a zero for all work performed during a class that you fail to attend. If you know in advance that you have a direct conflict with an upcoming class activity, please come speak with me about the nature of the conflict so that we can determine if a make-up assignment is possible. Note that this will not always be the case - particularly for laboratory experiments. In general, and unless something completely unforseen has happened (a natural disaster, etc.), you will only be allowed to arrange a make-up assignment for a missed class activity in advance of that activity. Please note that travel to and from vacation activities will NOT qualify for a make-up activity, so plan accordingly.


Unless you have cleared it with me before class, all electronic communication devices must be off and in a closed container during the entire class. No texting is allowed for any reason. If any cell phone rings during class, I will answer it. Repeat offenders (more than one such offense) will be asked to leave class along with their cell phones until they can figure out where the off button is.


If you have a documented learning disability, I am happy to set up any appropriate arrangements for testing, classes, etc.  Simply provide me with a letter from the Center for Disability Services, and let me know what I can do to make the class work for you.


None Required. Readings will be Located in the Class Blackboard Site under "Assignments".


234F New Science Building
Phone: 4067
Office hours Monday 2-3, Tuesday 1-2, Friday 1-3, Thursdays by appointment only. My
door is usually open if I am in.



Your final comprehension of the science concepts introduced in this class will be assessed during three unit exams, as indicated in the 'Schedule of Events' below. These exams will generally consist of two parts. The first part will contain 5-7 short answer questions that will be intended to assess your basic comprehension of unit concepts. You will be graded on all but one of the questions in this part, and you may choose which question to drop. The second part of the exam will contain one question that will evaluate your ability to synthesize and apply course concepts. All students will be required to complete part 2 in its entirety. The unit exams will be closed-book, individual efforts. If you are caught cheating on an exam you will receive a zero for that exam, and a letter will be sent to the Dean of Students.


Throughout the semester, you will be required to fill out short worksheets regarding your laboratory results. These worksheets may be team efforts.


Each student will write a final fermentation essay that will be due on the last day of class. The essay must describe the production of one type of fermented product that we have not specifically covered in class this semester (For example, you chould not choose Swiss Cheese, but could choose another type of cheese that we have not studied). In addition to clearly describing the microbial species and biochemical reactions involved in producing that product, the essay must also include information regarding the historical, religios, or social significance of the fermented product. More details will be provided in a separate handout.




The Microbiology of Beer, Bread and Cheese

Schedule of Events - Fall 2011

Unit 1: The Microbiology of Beer

Week 1 (August 29, Sept 2)


Introduction to The Microbiology of Beer, Bread and Cheese

Syllabus Overview, Class Ground Rules

Introduction to Fermentation

Week 1 Handout: Introduction to Fermentation; Printer-Friendly Version of the Syllabus

Week 2 (Sept 5, 9)

Beer Chemistry

Week 2 Handout

Week 3 (Sept 12, 16)

The Microbiology of Beer Through the Ages

Reading #1: Fermentation Theory and Practice: the Beginnings of Pure Yeast Cultivation and English Brewing, 1883-1913. Will be sent via Blackboard email.

Reading #2: Fermentation Technology 3,000 Years Ago- The Archaeology of Ancient Egyptian Beer

Week 4 Handout: Microbiology of Beer Through the Ages


Week 4 (Sept 19, 23)

Monday, September 19: Tour of Selin's Grove Brewing Company

Click on link to directions from campus here. Meet at 12:45 in back parking lot of the Brewing Company.

Friday, September 23: Beer Chemistry

Handout: Analyzing The Chemistry of Beer

Week 5 (Sept 26, 30)

Exam One. Review Sept 26, Exam Sept 30

Week 6 (Oct 3, 7)

Exploring Fermentation Lab #1: Brewing Beer

Handout: Brewing Beer

We will brew on October 3. We will meet at my house at 9:00 am and brew until we finish...probably 3-4 hours. I will send out notification to the professors in your other classes to let them know you have a field trip for my class. If you cannot attend the brewing session, I will arrange an alternative assignment for you.

There will be no class on October 7.

Week 7 (Oct 10, 14)

The Microbiology of Bread



The sourdough microflora: biodiversity and metabolic interactions

Flavour in sourdough breads: a review

Lactobacillus sanfrancisco a key sourdough lactic acid bacterium: a review

Week 8 (Oct 17, 21)

Fall Break

No Class October 21: Science in Action Day

Week 9 (Oct 24, 28)

Making Sourdough Starter Cultures

Handout: Making Sourdough Starter

The Chemistry of Beer

Handout : The Chemistry of Beer

Fermentation Worksheet #1

Week 10 (Oct 31, Nov 4)

Exploring Fermentation Lab: Baking Bread

Monday: Get bread baking instructions and worksheet.

Friday: Bring completed bread to class, along with completed worksheet.

Week 11

How Bread and Food Shape our Lives

Reading Assignment: Kills a Body Twelve Ways: Bread Fear and the Politics of “What to Eat?"

Reading Assignment: Bread Making and Social Interactions at the Amarna Workmen's Village, Egypt

Handout: How Bread and Food Shape our Lives

Week 12

Exam Two

Week 13

The Basic Microbiology of Cheese: Bacteria and Curd Formation

First Read: Cheese (Class Handout)

Then Read: Recent Advances in Cheese Microbiology


Thanksgiving Break!

Week 14

Beyond Bacteria: Mold and Ageing

Read: Biochemistry of Cheese Ripening


Artisinal Cheese Production

Field Trip to Penn Cheese - 12:30 pm "Sharp" (hehehe)

Directions from Susquehanna to Penn Cheese

Penn Cheese Website

Week 15

Final Explorations in Fermentation

Time and Place TBA

Final Fermentation Essay Due

Final Exam Period

Exam Three

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