Fungi have been used for thousands of years to modify foods and beverages. bread made without yeast fungi is flat. the addition of yeast to flat bread dough causes the dough to rise during baking. yeast uses the process of fermentation to release energy and that process produces carbon dioxide as a by-product. the carbon dioxide is responsible for making the bread dough rise. based on the data collected, the highest rising bread would use yeast, warm water and the addition of