"Making Dat Bread" The science and history of yeast

Today, I'm going to talk about a little micro-organism that is combined with flour and water and makes up a majority of our carbohydrate intake. The leavening agent in our scale's worst enemy. 

I’m not talking about beer. I meant bread.  

More specifically, how yeast interacts with bread and why it is important. 

To better understand why yeast is so important to bread making, we have to first understand what yeast IS. Historically, yeast is probably our most used industrial micro-organism. There is evidence that it was used in ancient Egypt, it’s mentioned in the Bible, and it’s theorized that it may have even been used before human beings even knew how to write. 

Fast forward to the 1860s when Louis Pasteur identifies yeast as a living micro-organism. Armed with information and time, humans were able to isolate yeast into pure culture form and mass-produce baker’s yeast. 

Yeast is a part of the fungi group and is similar to mold. It is a single-celled micro-organism that relies on sugar to grow. This is why it is so helpful in the process of brewing beer or making bread. 

Anyone who is familiar with bread flour knows that it has a high gluten-protein content. This is important to know because yeast snags its claws into the gluten-protein and breaks it down into sugar. Why should you care about this? Well, that attraction that yeast has to bread flour's sugar results in HOW bread comes out so fluffy.

During the "rising" process of bread making, yeast transforms the sugar in bread flour into carbon dioxide and ethanol. This is how we get those nice little pockets of air that create perfect grooves to spread our butter and jam on. 

It is not historically known when yeast was first used. The word itself translates to “foam” or “bubble,” so we can surmise that when it WAS used, it was kind of obvious what it did. The earliest evidence that we can find about yeast being used for baking comes from Egyptian ruins. Bread making chambers, grinding stones, and renderings of bakeries and breweries all point to the conclusion that humans knew what yeast was good/important for from the very beginning.