This is an easy one. The simple answer is "Yeast" which is a species of fungus. There are many, many different types of yeast that all have different properties and functions. Yeast is used mostly for two purposes: Making bread rise, and fermenting alcoholic beverages like beer. Any bread recipe starts with the instruction of mixing yeast in warm water and adding a little sugar. You let this mixture sit for a while until it starts to foam up. This is the yeast beginning to do its thing. The little "yeasties" are eating the sugar, and giving off carbon dixoide. When you mix the yeast mixture and the dry ingredients (according to the bread recipe that you are using) the yeast continues to feed on the sugar, reproduce, and expel more and more of the CO2 gas. It's the CO2 gas that "inflates" the dough and makes it rise.
Another species of yeast is used to make beer. Again, it is a chemical reaction that takes place when the yeast organisms eat the sugars in the grain used to make the beer. The yeast organisms reproduce very quickly, consume those sugars at an unbelievable rate, and emit CO2 and alcohol. Yes, it sounds kind of gross but alcohol is indeed "yeast-poop" and "yeast-farts" make bread rise.
Glad I could help.
Bernie
Another species of yeast is used to make beer. Again, it is a chemical reaction that takes place when the yeast organisms eat the sugars in the grain used to make the beer. The yeast organisms reproduce very quickly, consume those sugars at an unbelievable rate, and emit CO2 and alcohol. Yes, it sounds kind of gross but alcohol is indeed "yeast-poop" and "yeast-farts" make bread rise.
Glad I could help.
Bernie
