CALIFORNIA STATE SCIENCE FAIR 2004 PROJECT SUMMARY Name(s) Project Number Julia H. Pavicic 24380 Project Title Rising Up: Finding the Best Leavening Agent in Bread Baking Abstract Objectives/Goals My objective was to determine the most effective leavening agent in baking bread. I believe yeast will be the most effective. Methods/Materials Four loaves of bread were made using one master recipe and the single variable was the leavening agent. The same ingredients were used in each batch of bread and yeast, sourdough starter, baking powder or baking soda was added to the recipe. The experiment was repeated a second time. The volume of each loaf of bread was calculated initially as mixed dough, then again after first rise and again as baked bread. Results Yeast proved to be the most effective leavening agent, as the volume of the yeast bread dough was the largest after the first rise, and also largest after the bread was baked. Conclusions/Discussion Yeast is a living single cell organism. When mixed with sugar and warm water, the yeast "eats" the sugar and the process creates a gas called carbon dioxide. The gas causes the dough to rise. My master recipe contained the warm water and sugar necessary for yeast activation. Research shows that to make baking soda active, either buttermilk or another acidic ingredient is needed - my recipe contained neither. My conclusion might be different if I added into my master recipe all of the ingredients needed to activate the other leavening agents. Summary Statement Using a master bread recipe with the leavening agent as its only variable, my results show yeast is the most effective leavening agent in making bread. Help Received Dad provided an equationPreliminary for calculating the volume of an oval loaf of bread, mom took photos, mom did some of the typing and helped me create tables in Word. Ap2/04.