Biology report

The main purpose of this report is to identify two aspects of biology with are closely linked with the brewing industry and chose one to explain in detail. The audience to which this report is targeted at is A level students who have a good understanding of biology.

The first aspect I have chosen to investigate is the asexual reproduction of yeast within the brewing process. Yeast asexually reproduced during the sixth process of brewing. Asexual reproduction is very important within the brewing industry. Without it yeast could not reproduce with an identical genetic make up and without the identical genetic make up brewers could not control the taste of the quality of their beer. With asexual reproduction brewers can genetically modify the yeasts in search of a new/better taste and then reproduce them to the trillions needed without variation occurring. [3, 4, 5]

The second and major characteristic of the brewing process I have chosen is the fermentation of yeast, Saccharomyes ceivevisia in particular, within the brewing business to release ethanol. Fermentation is the anaerobic conversion of sugar to carbon dioxide and ethanol by yeast, this is another important process because without fermentation breweries could not exist as they would have no product to sell. I chose these topics after my visit to bass brewery in Stoke on Trent where I found some of my information. [2, 4, 6]

First aspect: Asexual reproduction

To survive all living things must reproduce. Yeast is one product which reproduces asexually, i.e. without a partner. It does so naturally, no chemicals or special circumstances are needed. All the ‘offspring’ are clones; they are genetically identical to the parent cell. This is also called mitosis and used in humans for growth and repair. Before each cell division a copy of each chromosome is made so that each cell has exactly the same genetic information. [3, 6]

Asexual reproduction (mitosis) takes place during fermentation where the cooled wort is ran through the fermenting vessels and the yeast is added. Fermentation then takes place (explained later) during fermentation yeast reproduces by budding. Budding is an asexual reproductive structure. The yeast reproduces as shown in the diagram above. The yeast can only be used 5/6 times as after this the DNA of the yeast may mutate. As yeast affects the flavor the mutations limit the amount of times the yeast can be used. This links back with one of the ethical issues surrounding asexual reproduction. All the yeast is kept the same as if they were to mutate and become different the taste of the beer would b affected. [ 3, 5, 6]

Issues surrounding asexual reproduction

Economical = as yeast reproduces asexually during the brewing process the brewery ends up with a lot more yeast than necessary. This could become a waste issue. However the brewery actually sells the yeast off to other companies to make an extra profit. Bakeries, for example, which use yeast in the production of bread. This is economically advantageous. [4]

Environmental = because the brewers don’t throw away the excess yeast they produce they become environmentally friendly, as less waste is then created, which is better for the environment. [4]

Ethical = yeast reproduces asexually, this means there is no variation, every cell is exactly the same unless a mutation occurs. As breweries only want certain types of yeasts to make certain tastes and textures other yeasts are not used left to become extinct. Some would say this is unethical of the brewery to pick and chose which yeasts survive and which become extinct and that every strand of yeast should have the same chance of survival.

Second aspect: Fermentation

Fermentation is a chemical process that has been used for thousands of years to produce alcohol and is still now used in the modern brewing process. Fermentation can be defined as the anaerobic conversion of sugar to carbon dioxide and ethanol by yeast. To turn the sugar from the wort (glucose) into ethanol and carbon dioxide the yeast uses an enzyme to break down the sugar molecules. The yeast in this conversion is an agent which just allows the break down to take place without being used up itself. In the actual brewing process fermentation is the sixth process to take place. [2, 4, 6]

Issues surrounding fermentation

Environmental = the brewers do not let carbon dioxide given out from the break down of yeast escape into the atmosphere as it is a green house gas and therefore linked to global warming. Instead they collect the gas and convert it into liquid for the use of making drinks fizzy. This is also economically efficient for the brewery as they can use the carbon dioxide they collect to make their own beer fizzy without having to pay for it. [2, 4]

Social issues = the main products of the brewing process are beers, spirits, and wines. Alcoholic drinks are harmful when consumed in excess. Excess alcohol can alter judgment and can lead to dependency and other health related problems. “Taking more than one drink per a day for women or two drinks per a day for a man can raise the risk of breast cancer, motor vehicle crashes, high blood pressure, a stroke, and violence” etc. “Alcohol consumption during pregnancy increases the risk of birth defects.” One could say that these reasons alone are enough evidence to claim that the process of fermentation shouldn’t take place. [1]

Ethical = as yeast is a living organism some might say that allowing yeast to die after it has completed its task is unethical. However I do not agree with this as yeast is a single celled organism and is therefore not complex enough to feel pain.

Leave a Reply

Your email address will not be published. Required fields are marked *