OBJECTIVE

Students will understand the components and processes involved in making bread. Students will experience the full process of sourdough fermentation and baking.

ESSENTIAL QUESTIONS

• Where does bread come from?
• What are the key ingredients in bread, and how do they contribute to the process of making bread?

MATERIALS

• Wheat Flour (whole wheat and white flour)
• Rice Flour
• Active Dry Yeast
• Sourdough Starter
• Wheat Kernels
• Water
• Salt
• Mixing Bowls
• Wooden Spoon/Spatulas
• Measuring Cups and Spoons
• Plastic Wrap or Damp Towels
• Baking Trays or Pans
• Oven
• Dough Scrapers
• Cloth Towels or Proofing Basket
• Microscope or Magnifying Glass
• Diagrams of Wheat Kernel
• Sourdough Bread for Tasting
• Wheat Threshing and Winnowing Tools

PROCEDURE

Lesson 1: Introduction to Wheat
Introduction: Bread is known as the “staff of life,” a staple food for many
civilizations, regarded highly because of its transformation through its rise. What
are the ingredients in bread? (think – pair – share)

• Water: why?
  o When water is added to wheat flour, gluten forms. Flour has glutens
  precursors (gliadin and glutenin proteins) which, when mixed with
  water, create breads extensibility and elasticity (stretch and shape)
• Salt: why? For flavor
• Yeast: discuss kingdom, characteristics
  o As bread and dough ferments, the yeast produces CO2 that causes the
  gluten network to expand
  o If gluten is too weak it can’t stretch in thin films around the air
  bubbles, causing the loaf to lack volume. If gluten is too strong, then it
  won’t stretch so the gas bubbles can’t expand and cause a dense loaf.
• Flour:
  o Wheat makes glucose for energy. Excess is stored as polysaccharide
  starch.
  o It’s starch (unlike others) can absorb water and won’t disintegrate at
  higher temperatures
  o Amylase, a naturally occurring enzyme in the flour, breaks down
  starch polysaccharides into monosaccharide for the yeast
  o Baking: during baking, wheat starch absorbs more water, taking it
  away from gluten strands and making them more rigid so that the
  bread stands firm and doesn’t collapse

Activities:

• Compare and discuss the difference between whole grain flour and white
  flour (show diagram of a wheat kernel)
• Make dough out of rice flour and wheat flour: compare the elasticity
• Thresh and winnow wheat
  Lesson 2: Make a Starter Culture

Introduction: Today we’re going to focus on the yeast ingredient in bread. What is
yeast? Where is yeast found?

• Pass around active dry yeast
• Pass around sourdough bread to taste: ask for student observations
• Discuss how sourdough is made from a starter culture that captures the
  yeast.
  o Somewhere in ancient Egypt, someone noticed that a forgotten bowl
  of porridge was bubbling and expanding – when it was heated in an
  oven it grew larger, trapping the bubbles in an airy yet stable
  structure that resembled a sponge.
  o Sourdough culture contributes not just air but texture and flavor. Wild
  yeasts and bacteria find their way into the batter, take up residence,
  and eventually organize themselves into a more or less stable
  microbial community.
  o A sourdough culture is made of specific yeast and bacteria strains
  suited to living together, each consuming different sugars. When the
  yeasts die, their proteins break down into amino acids that the
  lactobacilli need to grow. The lactobacilli produce organic acids that
  make the environment agreeable to the yeast we want but
  disagreeable to other yeasts and bacteria.

Activity: Make a sourdough starter

• Students should stir starter everyday to add in oxygen until the starter
  bubbles
• Once the starter shows vigorous bubbles, it needs to be fed every day. To
  feed it, take out 50% of it and feed it an equal mix of whole-wheat flour and
  white flour. Mix in water so that it is a moist dough consistency.
  Lesson 3: Introduction to Bread Baking
  Introduction: Today we’re going to make two simple doughs. One will be made
  with white flour and one will be made with a mix of white flour and whole wheat
  flour. As we work with these two doughs, what do you think will be different about
  them?
  Activity: Make white dough and a whole-wheat dough with active dry yeast.
• Teach students to knead dough. Notice the differences in each as they are
  kneaded.
• Do the “window test” with both doughs.
• If possible: Let the dough ferment and bake to eat that afternoon or the next
  day!
  Lesson 4: Bake with sourdough culture (ideally with school garden wheat!)