Yeast: Beer for the Ancient World and Biofuels for the Future

The microorganism that is responsible for making beer bubbly and humans giggly is yeast.   Yeast is an eukaryotic microorganism classified in the kingdom Fungi.  Saccharomyces cerevisiae is a species of yeast widely used in gastronomy, which is the art of good eating, and in research for Biotechnology.   S. cerevisiae is often thought of as the most useful species of yeast and it is one of the most intensely studied eukaryotic model organisms.  What makes this yeast so great?  S. cerevisiae is a single-celled eukaryote, so it shares the complex internal structure of plants and animals, but its genetic sequence is much more easily navigated by researchers when compared to more complex eukaryotic organisms.  It only takes 1-2 hours for S. cerevisiae to double in number, and it was the first eukaryotic organism with its entire genome (genetic code) sequenced.  It is credited with assisting in the identification of more mammalian genes affecting aging than any other model organism.  This species of yeast plays a pivotal role in the research of Cancer, Biofuel and many other consumer goods.  Visit:  &  <  via MIT News

Saccharomyces cerevisiae is a name derived from Latin and Greek.  Saccharomyces is the Latinized Greek word meaning “sugar fungus”.  Cerevisiae comes from Latin and means “of beer”.

How is yeast used to make beer?  There are generally four main ingredients in beer: water; grains (typically malted Barley); hops; & yeast.  First, the grain has to go through a process to be made into “Mash”.  The mash mixture is achieved by crushing the malted barley, which breaks up the kernel, and then adding water.  The mixture is then heated to convert the starch in the milled grains into fermentable sugar.  This is where our very important single-celled distant ancestor, Yeast aka Saccharomyces cerevisiae, makes the magic happen.  Simply stated yeast uses the sugar derived from “Mash” as a food source, which then produces the by-products of carbon dioxide and ethyl alcohol.  The carbon dioxide released by the yeast is responsible for bubbles in beer, and it is also what makes bread rise.  Ethyl alcohol is what some would say makes beer the nectar of the gods.

For the complete beer making process and our ancestral relationship to yeast visit the following:

Nice, Karim.  “How Beer Works”  12 December 2000. <;  30 March 2013.

Ancestral relationship:


Bad-yeast-litmus via