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Science Rocks!

Yeast, Part II


your results

Sent in by:
Cara of MD

Feed the yeast!

Materials Needed

  • 3 packages of yeast
  • warm water
  • 3 clear, 16 ounce, plastic water or soda bottles
  • funnel
  • 3 balloons
  • rubber bands
  • various sugary liquids, like cola, apple or orange juice, and corn syrup



  1. Check with a grown-up before you begin.
  2. Cara of Maryland sent us the idea to do an experiment to see which liquids yeast like the best. When Matt and Estuardo did this on the show, their hypothesis was that the more sugar a liquid has, the more the yeast will eat it, and the more carbon dioxide it will produce. Here's how you can test it out.
  3. Add 1 package of yeast to each bottle.
  4. Fill each bottle 1/4 full with warm water.
  5. Fill the first bottle half way full with one of your sugary liquids, like cola.
  6. Fill the second and third bottles with different sugary liquids. Make sure you add the same amount of liquid to each bottle.
  7. Put a balloon over the opening of each bottle. The balloon that inflates the most will show which liquid produces the most carbon dioxide.

Which of your liquids do you think will produce the most carbon dioxide? Make a prediction, and then test it out. Be sure to send your discoveries to ZOOM!

Some of your Results

Angela of Baltimore, MD wrote:
we used smaller bottles and I am wondering if that keeps the yeast from reacting as much

Hannah, age 10 of ID wrote:
the balloons went so high and really big it was amazing what the experiment did you should try it.

Jade, age 10 of Palmer, AK wrote:
I used italian soda, apple juice, and lemon water. the soda was the biggest one and lemon water was last.

Anne, age 11 of Torrance, CA wrote:
I tested sprite, coca-cola, and maple syrup. Maple syrup grew the least and Coca-Cola grew the most! It was really fun!!!

Maria, age 13 of Jeddah, Saudi Arabia wrote:
I used orange, apple, and cola juices. The orange's balloon blew the least, while the apple's juice balloon blew a bit more. The cola balloon blew a lot that it was going to burst!!!

Hajar, age 12 of Jeddah, Saudi Arabia wrote:
The bottle with 7up was the best because this liquid has more sugar than the others. Its ballon was larger in size.

Ali, age 12 of Jeddah, Saudi Arabia wrote:
I used cocktail juise and pepsi and 7 Up and the cocktail was the best but it took for it mush tima.

Assim, age 11 of Jeddah, Saudi Arabia wrote:
1-The yeast in the mixed liquid ate the sugar, react with it and produce carbon dioxide. 2-The more sugar in the mixed liquid the more carbon dioxide production. 3-Carbon dioxide inflated the balloons over the three bottles. 4-The yellow balloon was inflated more, then the red balloon then the white balloon. 5-As a result it is obvious that the orange juice (yellow balloon) has more sugar than strawberry juice (red balloon) while the Pepsi cola (white balloon) has less sugar than both.

Esraa, age 12 of Jeddah, Saudi Arabia wrote:
The soda took the oxgen becuase of the yeast.

Abdallah, age 12 of Jeddah, Saudi Arabia wrote:
The cola was having the most carbon dioxide and the ballon that is on the cola was big but the another two the ballon was so small!

Rakan, age 12 of Jeddah, Saudi Arabia wrote:
my hypothesiese was that vthe most bottle that has carbon dioxide is the bottle with thw cola sugar liquids. and the cola bottle it's ballon became big but the another bottle it ballons gets into the bottle and it does not become big.

Fatima, age 12 of Jeddah, Saudi Arabia wrote:
I saw how each baloon inflates slowly. The baloon that had to do with the cola was the most to inflate. Also it was the fastest to inflate. so I discovered from this experiment that the cola gives the most amount of carbon dioxide to the yeast among cola, orange juice & honey syrup.

Hoda, age 12 of Jeddah, Saudi Arabia wrote:
I make my experiment about yaest. I put 3 bottles the 1st: I put an apple juice, the 2nd: I put a lemon juice, the 3rd: I put 7up. Of course the 7up will flows more than the others. Really it was fantastic try to make it.

Jane of Brown Deer, WI wrote:
We used corn syrup, orange juice, apple juice and root beer. The corn syrup was the biggest, then orange juice, apple juice and then root beer. The next day the root beer's balloon lost gas and deflated. The corn syrup had a substance in it. We think it was yeast in the balloon. Our kids loved it, but it stinked!

Mazen, age 12 wrote:
The soda blew the most while the apple juice blew more than the maple syrup and less than the soda.

Faisal, age 12 of Jeddah wrote:
At first, I noticed that the apple juice was producing more carbon dioxide because the balloon grows faster, but in the end the size of the balloon didn't increase again. The 7up won. The balloon increased its size twice as the chocolate milk and the apple juice's balloons. So the 7up has more sugar than chocolate milk and the apple juice, the yeast like it much and it also produced more carbon dioxide than the others.

Peach, age 12 of CA wrote:
I did the experiment with apple juice(1st), water(4th), 7Up(3rd), and lemon juice (2nd). it was really fun. we ended up loosing some air in the apple juice and lemon juice but it was great still. hopefully my science teacher likes it!!

Hannah, age 12 of Saint Paul, MN wrote:
Instead of changing the type of liquide I used water and different amounts of sugar. I used 1 teaspoon of sugar, two teaspoons of water and 1 teaspoon of Sweet n low. The one teaspoon of Sweet n low produced the most carbon dioxcide. Then the 1 teaspoon of sugar. Following is the 2 teaspoons of sugar.

Haley, age 9 of New York, NY wrote:
the cola soda won!

Adaiah, age 9 of Sacramento, CA wrote:
I used root beer, lemonade, syrup, orange juice. The lemonade produced the most carbon dioxide. Yeasts grow best in a neutral or slightly acidic pH environment, thus the reason why lemonade produced more.

Alexa, age 12 of Simi Valley, CA wrote:
i did the project diff. I used 1 pac. of yeast, 1warm cup of water, 2tables. of sugar, balloon bottle. what happen was foam got in balloon where did the yeast go

Hailey, age 11 of Alice, TX wrote:
well we used diff. materials, but it was cool.

Alexis, age 11 of Fort Lauderdale, FL wrote:
I used grape soda, apple and orange juice. The apple juice blew up the most.

Tina, age 11 of Brooklyn, NY wrote:
It worked, but the balloon popped, can you tell me why? Ehh. The yeast got everywhere, yuck! I had to clean it alll upp!

Sheila, age 11 of Miami, FL wrote:
This experiment is so cool I am going to use it for my science fair project when I showed it to my science teacher he loved it.

Osmin, age 10 of Pomona, CA wrote:
Yeah, this project was really fun I really enjoy it, and yeah the soda inflated the balloon the most. Thank you this project really help me at my science fair project!

Justin, age 11 of Mitchellville, MD wrote:
Iused Coke, corn syrup, and grage juice. The Coke turned out to be the biggest ball.

Shirley, age 16 of Orange, NJ wrote:
Man, this experiment was really fun! When I did it the soda inflated the balloon the most. I used this for my science project this past year THANX ZOOMsci!!!

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