Yeast Fermentation Lab
Purpose:
To observe the process of fermentation.
To observe the effect of sugar amounts on yeast activity.
Background Research:
Hypothesis:
1. Hypothesize which group will have the largest balloon measurement.
2.
Hypothesize what substance will be inside the balloon at the end of the lab.
Materials:
package of dry active yeast
ruler or meter stick
250 mL beaker
string
250 mL flask
balloon
sugar packets (various amounts based on group)
warm water (110 ºF)
funnel
Procedure:
MAKE SURE TO READ DIRECTION BEFORE YOU START SO YOU CAN WORK QUICKLY. TIME IS VERY IMPORTANT
IN THIS LAB!!!!
1) Fill the beaker with 100 mL of warm tap water.
2) Add 1 package of yeast to the warm water and stir until it is in solution (dissolved).
3) Carefully pour the yeast solution into the flask using a funnel.
4) Complete the lab according to the group you have been assigned.
Group 1: After pouring the yeast solution into the flask, immediately place the balloon on the top of the
flask. Note the time on your lab chart. This will be your start time.
Group 2: After pouring the yeast solution into the flask, add 1 packet of sugar to the mixture and swirl it
gently until it dissolves. Immediately place the balloon on top of the flask. Note the time on your lab
chart. This will be your start time.
Group 3: After pouring the yeast solution into the flask, add 2 packets of sugar to the mixture and swirl it
gently until it dissolves. Immediately place the balloon on top of the flask. Note the time on your lab
chart. This will be your start time.
Group 4: After pouring the yeast solution into the flask, add 3 packets of sugar to the mixture and swirl it
gently until it dissolves. Immediately place the balloon on top of the flask. Note the time on your lab
chart. This will be your start time.
Group 5: After pouring the yeast solution into the flask, add 4 packets of sugar to the mixture and swirl it
gently until it dissolves. Immediately place the balloon on top of the flask. Note the time on your lab
chart. This will be your start time.
5) Using your string, measure the size of your balloon (in centimeters) at the largest diameter for the start
time and every 5 minutes after. Record the information on the data table.
Data:
Start Time
_______
SIZE OF BALLOON (in centimeters)
5 min.
10 min.
15 min.
20 min.
25 min.
Group 1
Group 2
Group 3
Group 4
Group 5
1)
2)
3)
4)
5)
6)
7)
8)
Questions
Which group’s balloon reached the largest size? Which group’s balloon reached the smallest size?
What were the variable(s) in this experiment?
Which group(s) was the experimental group(s)?
Which one of the group(s) was the control? Why was it the control?
What type of fermentation process was this?
What are the products this fermentation process?
What caused the balloons to increase in size?
What material was collected in the balloons?
Graph
Make a graph of the data by hand or on computer. Include a legend. Title and label all lines.
Conclusion:
THINGS TO THINK ABOUT WHEN WRITING CONCLUSION
I. Hypothesis Correct of Incorrect
Was each hypothesis correct or incorrect?
Hypothesis #1: _________________________________
Hypothesis #2: _________________________________
II. Have proof from data that determines if the hypothesis was correct or incorrect.
What data was used to determine if the conclusion of each hypothesis was correct of incorrect?
III. Analysis & Concepts – Discuss all aspects mentioned in purpose and background research.
How did this lab demonstrate fermentation?
What ingredients are needed to make the largest diameter of balloon?
Make sure to relate all the background research to this lab.