A PowerPoint that I made to illustrate how easy it is to make a Virtual Field Trip on the Chemistry of Bread. Suitable for Grades 4-8

1. The Chemistry of Baking breadSusan Sherrouse, TISFairview/Miss Jewell Elementary 1

2. The history of wheat Wheat grew in the Tigris and Euphrates River valleys nearly 10,000 years ago as a wild grass. Egyptians discovered how to make yeast breads between 2,000 and 3,000 BC. Wheat can now be grown almost anywhere, but is not native to the United States Click here to see the history of wheat 2

3. The wheat grain Wheat Grain Video 3

4. Milling the wheat Click here to see how flour is milled. 4

5. Ingredients for bread Flour is the bulking ingredient of bread, it forms the structure of the product. It contains gluten. Gluten helps to form an elastic stretchy dough. Yeast is a raising agent. Yeast produces gases to make the bread rise. Because it is living, correct conditions are needed for growth - food, warmth, time and moisture. 5

6. Ingredients for Bread Salt is required to bring out flavour in the bread. This ingredient is used in small quantities. Too much of this ingredient will stop the yeast from growing. Yeast needs energy to grow. Sugar provides the food for the yeast; it is needed to help the yeast grow. 6

7. Ingredients for bread Kneading is done to develop gluten and the make the dough stretchy and smooth. It allows the bread to rise more easily. Warmth helps the yeast to grow. If it is too hot it kills the yeast, too cold it will slow the rising process. 7

8. Ingredients for Bread Bread needs time to rise. The yeast needs this to grow and double in size, in order to properly make bread. Water is used to bind the flour together and helps to form the structure of the bread. It needs to be warm to help the yeast grow - about 98.6°F. It should feel about the same temperature as your finger. 8

9. Ingredients for bread Fats or oils improve the texture of the bread, preventing it from going stale quickly. Click here to see how bread is made from scratch. 9

11. One envelope of ‘rapid-rise active dry yeast’

12. One cup lukewarm water, about 100 F.

13. ½ cup sugar10

15. Add ½ cup of sugar to the water and yeast.

16. Pour the entire mixture into the bag.

17. Put the plastic bag in a ‘warmish’ place’

18. Come back in one hour.11

20. The bag has partially filled with carbon dioxide gas, and the water is filled with bubbles .

21. Yeast produces carbon dioxide and ethanol (2 molecules of each)

22. There are billions of yeast molecules in a packet of yeast.

23. In two hours, the bag should be puffier.

24. Here is a video with interesting experiments12

26. We eat the equivalent of over 9 million large loaves of bread every day.

27. There are three basic types of bread - white, brown and whole meal - but more than 200 varieties are available to the consumer.13

29. Bread provides more protein, iron, B vitamins and complex carbohydrates per penny than any other food.

30. Bread is the major source of fiber in our diet, providing a quarter of our daily intake.

31. Bread contains very little fat and virtually no sugar14

32. Resources used to make this VFT Discovery Streaming YouTube www.tramline.com http://trackstar.4teachers.org/trackstar/ 15

33. Now, to leave with a…. BANG! 16