Yeast Fermentation Lab
Mark Duanmu, Rika Fujita, Alex Chung
October 8, 2011
Biology (Honors) P7
Gill
Temperature and Yeast Fermentation
Introduction:
Saccharomyces cerevisiae, commonly known as baker’s yeast, is an key ingredient used mainly when baking bread or making alcoholic beverages. The main role of the yeast is to convert the sucrose into carbon dioxide (CO2) and ethanol. For example, when baking bread, the yeast ferments the sucrose within the dough and so CO2 and ethanol is released, causing the bread to rise and expand. It does this using enzymesAlso, during this fermentation process, because CO2 is released, it starts to form foam and that is why, for example, beer, ends up with a layer of foam above the liquid.
Yeast undergoes an alcoholic fermentation, where it first ferments the reactants, glucose. Glucose, C6H12O6, is then transformed into ethanol (2 C2H5OH) and carbon dioxide (2 CO2).
The purpose of this lab is to find out what effect changes in environmental temperature has on yeast fermentation. To accomplish this, we would need to simulate yeast fertilization, have different temperatures to test it on, and a way to calculate and measure the amount of fertilization. To simulate fertilization, we put 4 tespoons of sucrose with 3 teaspoons of yeast in a glass jar, then added 50 mL of water, to start the reaction. We knew that in order to test the effect of temperature, you would need to change the temperature in the reaction, but also in the environment. So, we put each of the jars in 200mL water filled beakers, which had the same temperature as inside the jar. We also knew that fertilization releases carbon dioxide, so to measure the yeast fermentation, we used a CO2 probe, which was a baton-shaped device that we put in the jar, and it would measure the amount of CO2 in the jar. The CO2 probe connected to a computer, and using logger pro, we would see the change of CO2 during the reaction for 100 seconds, through a graph and a table. The greater the
October 8, 2011
Biology (Honors) P7
Gill
Temperature and Yeast Fermentation
Introduction:
Saccharomyces cerevisiae, commonly known as baker’s yeast, is an key ingredient used mainly when baking bread or making alcoholic beverages. The main role of the yeast is to convert the sucrose into carbon dioxide (CO2) and ethanol. For example, when baking bread, the yeast ferments the sucrose within the dough and so CO2 and ethanol is released, causing the bread to rise and expand. It does this using enzymesAlso, during this fermentation process, because CO2 is released, it starts to form foam and that is why, for example, beer, ends up with a layer of foam above the liquid.
Yeast undergoes an alcoholic fermentation, where it first ferments the reactants, glucose. Glucose, C6H12O6, is then transformed into ethanol (2 C2H5OH) and carbon dioxide (2 CO2).
The purpose of this lab is to find out what effect changes in environmental temperature has on yeast fermentation. To accomplish this, we would need to simulate yeast fertilization, have different temperatures to test it on, and a way to calculate and measure the amount of fertilization. To simulate fertilization, we put 4 tespoons of sucrose with 3 teaspoons of yeast in a glass jar, then added 50 mL of water, to start the reaction. We knew that in order to test the effect of temperature, you would need to change the temperature in the reaction, but also in the environment. So, we put each of the jars in 200mL water filled beakers, which had the same temperature as inside the jar. We also knew that fertilization releases carbon dioxide, so to measure the yeast fermentation, we used a CO2 probe, which was a baton-shaped device that we put in the jar, and it would measure the amount of CO2 in the jar. The CO2 probe connected to a computer, and using logger pro, we would see the change of CO2 during the reaction for 100 seconds, through a graph and a table. The greater the