Baking Bread RP Partners: GA DM May 11, 2017 For this lab report we made three different loaves of bread, each with a different leavening agent. We made one with baking soda, one with yeast, and one with sourdough starter. Leavening agents are used because they help baked goods rise. When leavening agents are added to the dough, the leavening agent will eat the sugars from the flour and release CO2 which causes the dough to expand. Yeast takes longer to rise and is a biological leavening agent and is our control group. The sourdough and the baking soda bread use different kinds of leavening agents and are our experimental groups. We will measure the change in volume of the bread before and after cooking it to see which is the best leavening agent. My hypothesis is that the bread with the biological leavening agent, yeast, will release the most CO2 and so rise the most because people have been experimenting with it for thousands of years. However, it is interesting to see how well other modern leavening agents work compared to yeast because so many people use them. There is no time to make all three of the breads, so my group made the baking soda bread. Ingredients​: Yeast Bread (Control Group) Ingredient
Calculations
Revised Amount
3 Cups Water
3 divided by 4 =
3/4 cups of water
6 1/2-7 1/2 Cups All-Purpose Flour
6 1/2 divided by 4 =
1 5/8 cups flour
1 Tablespoon Salt
1 divided by 4 =
1/4 Tablespoons of Salt
1 1/2 Tablespoons Yeast
1 1/2 divided by 4 =
3/8 Tablespoons of Yeast
Sourdough (Experimental Group 1) Ingredient
Calculations
Revised Amount
4 cups of water
4 divided by 4
1 cup
10 cups of all purpose flour
10 divided by 4
2 1/2 cups
¾ cups of sourdough starter
3 1/4 divided by 4
13/16 teaspoons
3 ½ teaspoons salt
¾ divided by 4
3/16 cups
Baking Soda Bread (Experimental Group 2) Ingredient
Calculations
Revised Amount
3 ½ cups flour
1* 3 ½ = 3 ½
3 ½ cups of flour
1 teaspoon of sugar
1*1=1
1 teaspoon of sugar
1 teaspoon of baking soda
1*1=1
1 teaspoon of baking soda
1 teaspoon of salt
1*1=1
1 teaspoon of salt
2*1 =2
2 cups of buttermilk
2 cups of buttermilk Procedures: Yeast Bread (Control Group) 1. Combine all of the ingredients in a bowl. 2. Mix everything until you get a sticky dough. 3. Let your dough rise at room temperature or in the fridge for 2 hours 4. Bake the dough at 450 F for 25-35 minutes or until golden brown. 5. Let the bread cool for 1-2 minutes.
Sourdough (Experimental Group 1) 1. Mix all of the ingredients together. 2. Knead the dough for 10 minutes. 3. Let the dough rise for 4-6 hours at room temperature or 10 hours in the refrigerator. 4. Bake it for 40 minutes to 1 hour at 500 F. 5. Let the bread cool and eat. Baking Soda Bread (Experimental Group 2) 1. Mix all of your ingredients together in a bowl, except the buttermilk. 2. Add the buttermilk after all of the dry ingredients are mixed. 3. When you have your dough, do not knead the dough because it will become very heavy. 4. Place your dough on a baking sheet and cut an X in the middle so the air can escape. 5. Bake the bread at 450 F for the first 15 minutes, then at 400 F for 20-30 minutes for or until golden brown. 6. When it is done, stick a thermometer inside the bread and make sure it is 195 F to 200 F. Variables
Variable
Flour type
Dough rise time
Control Group (Commercial Yeast Bread)
Experimental Group 1 (Sourdough)
Same
Experimental Group 2 (Commercial Leavening Agent Bread) Same
15-60 minutes
5 minutes
500 F
450 F for 15 minutes, then 400 F for 20-30 minutes more
2 hours
40 minutes
2 hrs at room temperature and 2 hrs-7 days in the refrigerator
Oven temperature 450 F Bake time 25-35 minutes
Dough amount
Full recipe ¼ of recipe
¼ of recipe
Other
Sugar and buttermilk
Results This table summarizes what we observed from our controlled experiments. Observation Height
Control Group
Experimental Group 1
Experimental Group 2
6.5” by 4” by 2” = 52 7” by 4” by 2”= 56 in^3 in^3 6.5” by 4” by 2.75” = 8” by 4.5” by 3” = 71.5 in^3 108 in^3 Percentage Change: Percentage 28% increase Change: 108% increase
8” by 8” by 2.5” = 160 in^3
Taste
It tasted perfect. It was a perfect balance of everything
Did not taste, but heard it was very salty.
It tasted awesome and flaky. I tasted a bit nutty.
Appearance (holes, airiness)
It looked a little burnt around the crust and very soft and shiny in the center.
It was very round, hard, and crunchy.
It looked a little burnt around the crust.
Texture
It was a little tough to chew but a perfect consistency.
It was very hard
The crust was hard and chewy. It was soft in the middle.
8” by 8” by 4” = 256 in^3 Percentage Change: 60% increase
Nutrition Below is shown the daily nutrition percentage if one eats the baking soda loaf of bread. One can get most of one’s daily nutrients from this bread. Serving Size: 1 Loaf ● Calories 1400+240=1640. 66% of your daily usage nutrition. (= 1640/2500) ● Carbohydrates 4 g from sugar + 322 g from flour + 24g from butter milk = 350 g 88% of my daily usage nutrition. (= 350/400) ● Fat 6g. 7% of our daily usage. (= 6/78) ● Protein 50 g. 89% of my daily usage nutrition. (= 50/56)
Analysis: It appears the largest percentage change in volume came from our control group which was the yeast bread. Clearly, this releases the most amount of CO2. The percentage increase in volume for the yeast bread was 108%. This was far larger than that for sourdough, 28%, or the baking soda bread, which was 60%. The chart below shows the change in volume for each experiment before and after baking.
It appears that the leavening agent in the sourdough was not very successful because the volume changed very little. I suspect that this is because we did not make the sourdough bread properly. It was very crunchy and tasted like it had too much salt in it. The baking soda bread worked quite well, but not as good as the yeast in increasing volume. I believe that the baking soda bread tasted the best. It is also the easiest and fastest bread to make out of the three. Bread is very nutritious. One can get most of one’s daily nutrition from a loaf of bread. This
shows that bread was indeed very useful for the first farmers to grow flour and why the Agricultural Revolution was so important. Conclusion We did a control experiment making three loafs of bread with different leavening agents. The bread made with the yeast leavening agent showed the greatest increase in volume. Humans have been making bread with yeast for thousands of years so even though using baking soda is easier to make bread, it is better to make bread with yeast. This proved my hypothesis even though I was a little surprised by the results because I thought scientists would have made a better leavening agent. Appendix Pictures of our breads after baking.
Yeast Bread (Control Group)
RP(2017) Yeast Bread Sourdough (Experimental Group 1)
RP(2017) Sourdough Bread Baking Soda Bread (Experimental Group 2)
RP(2017) Baking Soda Bread