The Reaction of Different Yeast
to Different Types of Food
Sources
By:
Samantha Addington,
Paulina Manrriquez,
Mackenzie Staples,
and Zach Morgan
Purpose
The purpose of this lab was to find out which combination of different yeast and sugars in hot
water would go through cellular respiration most quickly.
Research
Yeast (Saccharomyces cerevisiae) is a single-celled fungus that comes in multiple
varieties such as Brewer’s Yeast, Baker’s Yeast, Fast Rise Yeast, etc. Yeast, like all living things,
go through cellular respiration, both anaerobic (without oxygen) and aerobic (with oxygen),
which is the process of breaking down food for energy. Yeast can go through both kinds of
anaerobic respiration, alcoholic fermentation and lactic acid fermentation. Brewers mainly use
yeast because of their ability to go through alcoholic fermentation, a form of anaerobic
respiration whose product is pure alcohol, and lactic acid fermentation, another form of
anaerobic respiration whose product is a wine-like substance. Yeast is also used very often with
bakers for their ability to go through aerobic respiration, a kind of cellular respiration where
glucose and oxygen are broken down to make energy with CO2 as a waste product, that, when
expelled from the yeast cells, makes bread rise.
Hypothesis
If we test three different kinds of yeast with 2 different types of sugar, then the name brand
yeast will react the most with the sprinkles.
Procedure
1. Get 10mL Freischman’s active dry yeast, 10mL Red Star active dry yeast, 10mL of Red
Star quick rise yeast, 3mL of pure cane sugar, 3mL of sprinkles, 120mL of hot water, and
6 test tubes.
2. Measure 5mL of Freischman’s active dry yeast in two test tubes. Measure 5mL of Red
Star active dry yeast in 2 test tubes. Measure 5mL of Red Star quick rise yeast in two test
tubes.
3. At this point, you should have two test tubes of each type of yeast. In one of the two
test tubes, put in 1mL of plain white sugar. In the other test tube, we put 1mL of orange
sugar. Do this for each type of yeast.
4. Add 20mL of hot water to each test tube.
5. Cover each tube with a balloon.
6. Record observation every 2 minutes for 6 minutes.
Data
Test Tubes
Amount
How much the balloon fills
up?
Test Tube 1
Freischmann’s Active Dry Yeast
with Pure Cane Sugar
Yeast: 5mL
Sugar: 1mL
Hot Water: 20
mL
2 mins.=Balloon is sticking
up
4 mins. =Balloon starts to fill
up
6 mins. =Balloon size
increased
Test Tube 2
Freischmann’s Active Dry Yeast
with Sprinkles
Yeast: 5mL
Sprinkles:
1mL
Hot Water: 20
mL
2 mins.=Balloon is sticking
up
4 mins. =Balloon is sticking
up but no air
6 mins. =Size increased by
a little
Test Tube 3
Red Star yeast (Active Dry)with
pure cane sugar
Yeast: 5mL
Sugar: 1mL
Hot Water: 20
mL
2 mins.=Balloon is filling up
4 mins. = Balloons starts to
fill up more
6 mins. =Balloon size
increased
Test Tube 4
Red Star yeast (Active Dry) with
sprinkles
Yeast: 5mL
Sprinkles:
1mL
Hot Water: 20
mL
2 mins.=Balloon is sticking
up
4 mins. =Balloon starts to fill
up
6 mins. =Balloon size
increased
Test Tube 5
Red Star (Quick rise) with pure
sugar
Yeast: 5mL
Sugar: 1mL
Hot Water: 20
mL
2 mins.=Balloon is still not
sticking up yet.
4 mins. =Balloon stood
6 mins. =Balloon filled up
Test Tube 6
Red Star (Quick rise) with sprinkles
Yeast: 5mL
Sprinkles:
1mL
Hot Water: 20
mL
2 mins.=Balloon is filling up
4 mins. =Balloon size
increased
6 mins. =Balloon size
increased more
Results
Based on the data from lab the most inflated balloon was test tube six.This test tube
contained Red Star Quick Rise yeast with sprinkles.The least inflated one was the test tube two.
This test tube contained Freischmann’s yeast and sprinkles. Two out the three with the
sprinkles were inflated compared to cane sugar. Two out of three of the pure cane sugar were
well inflated. Something that would have make our lab better is to keep all the balloons the
same and make sure the were all well placed.
This picture was taken at 2 minutes into the lab. The orange balloon is the Red Star quick rise
with sprinkles, and the pink balloon is Red Star active dry.
This picture was taken 4 minutes into the lab. As you can see, the Red Star quick rise (white
balloon in bad left) that had sugar in it is now standing up.
This picture was taken 6 minutes into the lab. All balloons are standing and starting to fill up.
The Red Star quick rise (orange balloon) is the fullest.
Conclusion
In our lab, we tested how different yeast reacted to different sources of sugar. We did
this by starting with two test tubes of the following; 5mL of name brand active dry yeast, 5mL
of generic active dry yeast, and 5mL of generic quick rise yeast. Then we put 1mL of regular
white sugar in one tube for each of the different yeast, and in the other we put 1mL of orange
sprinkles. Then after that, we added 20mL of hot water to each of the test tubes. We then
mixed the test tubes and added a balloon on the top of the tube. At the end of the lab, we saw
that the balloon that was Red Star active dry yeast with sprinkles filled up the most. In our
hypothesis we said that the name brand yeast will react more in the sprinkles. We were wrong
about the name brand, because the generic quick rise yeast reacted the most to the sprinkles.
I think this experiment was a great way to see how yeast reacted to different food
sources. By keeping the amount of each product the same, and the same amount of water, it
was easy to determine which type of yeast and which sugar would react more than others. We
did run into a little bit of trouble with timing. I would of like to do the experiment more than 6
minutes, to see if over a period of time the yeast would react more. If we were to do this
experiment over again, we would have used our time more wisely. We would also use different
types of sugar.