And there is always the chance that, due to a procedural error or unexpected contaminant, your batch of beer will turn out to be undrinkable. Beer is a mixture of barley malts or wheat, hops, yeast, and water. Water is a substance we are all familiar with, and for brewing purposes, the purer the better. The grains give beer its body, color, and flavor. Hops also act as a natural preservative.
Yeast is the organism that makes the whole process work.
The yeast digests the sugars from the grains and give off carbon dioxide and alcohol as by products, thus carbonating the solution and adding the alcohol kick we all know and love. The water, grains and hops are mixed in varying quantities and cooked at a boil for 45 minutes to an hour, sometimes longer. The resulting mixture is known as wort. Once the wort cools, the yeast can be pitched into the solution and the mix is then allowed to ferment for a week to ten days. This is when the yeast does its dirty work, converting the complex sugars of the wort into alcohol and CO2 and turning the concoction into beer.