Sunday, December 5, 2010

Sam's science project :Bread

Sam needed to do a science experiment for school. He is in 6th grade so they want something more than a baking soda volcano. We decided to do bread. Not just any bread, but two kinds of bread......
Leavened and Unleavened bread. For those of you who don't know the difference - unleavened bread has no type of rising agent and leavened bread does. So here is the fun we had :

Sam always has to make a silly face. Mia is having a good time.

Unleavened bread

again with the silly face

Our leavened bread

Here is the paper he will turn in....
1. How does a leavening agent affect bread?

2. Variables

a. The independent variable is adding a leavening agent (yeast in this case). Yeast makes the bread rise due to fermentation of sugar into carbon dioxide.

b. The dependant variable is the process of cooking

c. The constant is the flour.

Hypothesis: If the amount of the leavening agent increases then the puffiness of the bread increases. Therefore if there is no leavening agent the bread will be flat.

Materials needed: Bowls, measuring cups, measuring spoons, stirring spoons, oven, loaf pan and square pans, rolling pin, milk, butter, warm water, yeast, sugar, salt, flour, oil and eggs.

Instructions: Unleavened Bread: 1.combine dry ingredients. 2. Combine eggs and oil, and then beat. 3. Add eggs to flour, add milk, and then beat for 2-3 minutes. 4. Place into 2 – 8” greased square pans. 5. Bake for 20 minutes @ 450 degrees F.

Leavened bread: 1. heat milk and butter in small saucepan over medium heat. Remove from heat when butter is melted, set aside to cool. 2. Pour ½ cup warm water into small bowl. Slowly pour in yeast while stirring. Set aside for 5 minutes while doing next 2 steps. 3. In large bowl add sugar, salt and 1 cup warm water. Mix. 4. Check small saucepan. If it is warm to touch pour into large bowl and mix. 5. Begin mixing flour one cup at a time. By the time the 5th cup is used the dough will begin to get stiff and difficult to mix with wooden spoon. Turn dough onto floured board. Knead dough while continuing to add flour. Knead flour into dough until smooth, not sticky. 6. Grease large bowl with butter. Put bread dough into bowl. Turn so top of dough is buttered. Cover with towel. Let dough rise until doubled in size or about an hour. 7. Punch down dough. Turn it out on top of floured board and knead out bubbles for 5 minutes. Divide in thirds and form each loaf by rolling dough into rectangles. Roll dough like a jelly roll. Pinch seams closed. Pinch and tuck edges under loaf. 8. Preheat oven to 375 degrees F. Butter 3 mini loaf pans. Set loafs in pans, cover with towel and allow to rise until doubled in size (about 30 minutes). 9. Bake for 30 minutes 10. Remove loaves from pans and allow to cool before cutting.

See table

See graph

Conclusion: The hypothesis was correct because it said if the amount of the leavening agent increases then the puffiness of the bread increases. Therefore if there is no leavening agent the bread will be flat. The yeast worked in the bread by making carbon dioxide out of sugar. This caused the rising or “fluffiness” to appear. The experiment followed these guidelines, therefore proving the hypothesis correct.

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