Yeast is a necessary ingredient in many baking and brewing processes. Yeast can be used to make breads and xylitol gum. Breads are other carbohydrate foods are one of the oldest forms of food, which have sometimes incorporated yeast. Xylitol is a sugar alcohol that is commonly used as a sweetener in place of sugar, corn syrups, and pure sucrose. Yeast is especially diverse in the production of food, and that is its primary use to human kind although the greater biological world has more uses for yeast. Brewing yeast is especially essential in the initial processes of brewing, the wort fermentation.
The history and biology of yeast gives a brief context in which to understand the usefulness of yeast to humanity especially in the process of brewing yeast. Since yeast has been discovered over fifteen hundred different kinds have been found and identified. The largest grouping of yeast has been found in the ocean and falls under the categorization of ssaccharomycotina under the Fungi kingdom. These biological organisms produce asexually although some have been found to reproduce under binary fission. For the simplicity of the cell structure and the predictability of yeast, it is commonly used in living organism models and genetics to study cell biology. Yeast is a living organism with many variations that are found around the world.
Yeast is used in a variety of different cooking dishes and breads as well as being used in brewing. Yeast in brewing is broken down into two primary distinctions, top-fermenting and bottom-fermenting yeast. This delineation is fairly straightforward and logical as it follows the locations in the fermentation vat that the yeast primarily resides. Although as with many rules this does not always occur and the yeast will usually work through the entire wort mixture in the production of beer. Brewing yeast is subdivided beyond just top and bottom under the types of beer they produce, the temperatures at which they cook, and the flavors that each beer retains. Top fermenting yeast is known for cooking at higher temperatures, usually 61 or 75 degrees Fahrenheit which produces a sweeter beer more stereotypical of an ale style beer. Bottom fermenting beers are known for growing at lower temperature and leave a crispier flavor to the beer, giving it a flavor more stereotypical of a lager style beer, although this is not always true as it has been used to create ale style beers as well. One last differentiation should be noted and that is that top-fermenting yeast produces a beer with a higher alcohol content than bottom-fermenting beers. Brewing yeast is critical in the fermentation process as one step in the production of beer that chemically alters the composition of the beer creating an alcohol content so that the post-yeast wort can actually be called a beer.
Brewing yeast is important to the production of beer. In wines it is know as distilling, but this article will focus on its impacts to beer. Either in mass or small scale production brewing yeast is a necessary step in the brewing process because it enables the breakdown of the wort into a substance that is closer to resembling the beer that people the world over have come to enjoy.