1. The Fermentation of Beverages by Yeast
By: Anna Gillin
Grade 9
Hello my name is Anna Gillin. I am in ninth grade at the Academy of Notre Dame. My experiment is titled The Fermentation of Beverages by Yeast.

2. Problem Which common beverage has the highest sugar concentration?
Childhood Obesity is a growing problem in the U.S. One of the major links are intake of high sugar sodas and juices. I wanted to figure out which common beverage had the highest sugar concentration.

3. Research Sources Sugar Yeast CO2 Fermentation
In my experiment the three areas of research were sugar, yeast, and the process of fermentation

4. Research
These are the sugars found in the beverages used in the experiment
Coke- 27 g of sugar per 240 ml
Fructose
Glucose
Pepsi- 28 g of sugar per 240 ml
Diet Pepsi- 0 g of sugar per 240 ml
Aspartame
Hawaiian Punch- 20 g of sugar per 240 ml
Fructose
Glucose
Apple Juice- 31 g of sugar per 240 ml
Sprite- 27 g of sugar per 240 ml
Each of the beverages, except Diet Pepsi, contain high fructose corn syrup which is a liquid mixture of about equal parts of glucose and fructose from corn starch

5. Research
Yeast
Microscopic single celled organisms that are classified in the Fungi family
Can utilize sugars both aerobically and anaerobically
Baker’s Yeast
Common strain of yeast used as a leavening agent in baking bread
Produces ethanol and carbon dioxide from sugars anaerobically
Aerobically, yeast converts glucose to CO2 and H20
Anaerobically, yeast ferments glucose producing alcohol and CO2

6. Research Fermentation
Fermentation of a sugar will result in CO2 gas and alcohol production
Fermentation is a chemical reaction caused by the interaction of a food molecule and a substance
Sugar is food for yeast. Sugar encourages yeast to ferment faster, thus producing more CO2
In my experiment the sugars in the sodas are the food molecule and the substance is yeast

7. Hypothesis
If the beverage produces more bubbles of carbon dioxide through fermentation, then its sugars are best utilized by yeast.

8. Materials Graduated Pipet Paraflim Yeast- 10 ml per drink solution
Water- 10 ml per drink solution
Drink Solutions- 10 ml of each solution
Diet Pepsi
Coke
Pepsi
Apple Juice
Sprite
Hawaiian Punch

9. Procedure 177 ml of each of the beverages were boiled
Each of the tubes were labeled with the name of the drink solution
Yeast was added to the drink solution and withdrawn into a small syringe
A piece of paraflim was placed over the syringe to keep the solution inside
The height of gas bubbles in the syringe was measured
The procedure was continued for each of the drink solutions
The procedure was repeated for 3 trials
177 ml of each of the beverages were boiled at a rolling boil for 6 min. to lose its carbonation
The amount of gas bubbles trapped in the syringe was measured in 10 minute intervals for 30 minutes

10. Procedure The independent variable is the beverages.
The dependent variable is the CO2 production.
The control variables are the water and glucose.
The constants are the boil times and amount of materials used such as yeast and beverages.

11. Data
I performed 3 trials for each of the six beverages. I measured the level of CO2 at 10 min. intervals for each trial. At the end of each trial, I took the last measurement for my data analysis. From my graph, you can see Diet Pepsi had no carbon dioxide levels. In the absence of sugar, fermentation did not occur. The other beverages that contained sugar produced carbon dioxide. The beverages with high grams of sugar produced higher levels of CO2.

12. Conclusion
The hypothesis stated that if the drink produced more bubbles of CO2 then its sugars are best utilized by yeast.
The hypothesis was supported because Diet Pepsi, which doesn’t contain any sugars, did not ferment.
Greater grams of sugar do not necessarily result in higher levels of CO2. Case in point would be apple juice, which contains 31 g of sugar which was the highest amount of sugar in a drink but was produced a lower amount of carbon dioxide compared to several other beverages.
I concluded that the other beverages had High Fructose Corn Syrup which caused a quicker reaction to the yeast than apple juice contained natural sugars.
Also whenever sugar is present and accompanied by yeast then CO2 will produced

13. Improvements
The experiment could be expanded by adding another drink with natural sugars such as orange juice.
A more in depth study would be examining the consumers of these beverages and their health and weight affected by the high correlation of the sugars in drinks.
An additional beverage with natural sugar could be included to further my findings, in that natural sugar ferments at a slower rate than High fructose corn syrup.
This has been and still is a high profile topic that we should all be concerned about.
Many diseases have been linked to Childhood Obesity such as Type 2 Diabetes, High Blood Pressure, and Heart Disease.
Interesting enough, many people think Apple Juice is a healthy alternative to soda though as my experiment shows apple juice has a high content of sugar

14. Works Cited
Fogel, Robert. "Fungal Factories: Gasohol and more." Fun Facts about Fungi.      N.p., 13 Nov Web. 21 Feb <      FunFacts/Fermentation.htm>.
"5 Types of Soda and Why You Should Avoid 4 of Them." Fit Hacks. N.p., 22 Feb.      2008. Web. 21 Feb <      the-5-types-of-soda-and-why-you-should-avoid-4-of-them/>.

15. Works Cited
"Baker's Yeast." Wikipedia. N.p., 18 Feb Web. 21 Feb      <
"Apple juice, canned or bottled, unsweetened, without added ascorbic acid."      Nutrition Data. N.p., 20 Aug Web. 21 Feb      <

16. Thank You
Please feel free to ask any questions regarding my experiment
Thank you, I hope you enjoyed my presentation and found it informative