Rootbeer Fermentation

Rootbeer Fermentation

Recipe:
Clean, empty, plastic bottles and caps
Large Bowl
Funnel
Mixing spoon
Water (preferably spring water)
Bakers yeast (the dry kind)
Root beer extract
Sugar
Measuring spoons and cups

1. Dissolve 1/8 teaspoon of yeast in ½ cup of very warm water. Let stand for 5 minutes. Being in warm water activates the yeasts, and wakes them up from being dried out. Spring water, incidentally, makes better root beer than tap water.
2. Using the bowl, combine 1 ½ - 2 tablespoons of Root beer extract with 1 1/8 cups of sugar in warm water, to dissolve the sugar.
3. Add the two mixtures to the bottle and add warm water to bring the level of the liquid up to two liters. (Be sure to use very warm water). Fill the bottles to within 1 ½ to 2 inches from the top. Close tightly and hold upside down to check for leaks. Make a label out of plain white paper, and put your names on it. Tape the label to the bottle.4. Age the root beer for 3 or 4 days in a warm, dark place. Then store in a cool, dark place for 2 more days. Refrigeration will stop the fermentation process and kill the yeast. Total aging of at least one week is recommended. Two weeks will improve the flavor. Be sure to check the bottles every day for tightness, if they get too pressurized, they will explode. Never use glass bottles!
5. Chill root beer and taste. You may be surprised at how different this root beer is from store-bought root beer.

Science:
Root beer was made by our forefathers by soaking Sassafras (a type of tree) root in water, and adding sugar and yeast (yeast for carbonation). In the early 1900's however, scientists discovered that safrole, a chemical found in Sassafras root, was a carcinogen (which means it is a cancer causing agent). Now, a mixture of other herbs and spices makes up "root beer extract" which is what we now use to make homemade root beer.
Cellular respiration is the breakdown of sugar (glucose) to form ATP (a form of energy for an organism). There are two types of respiration: aerobic (requiring oxygen) and anaerobic (without oxygen). Yeast cells (a type of fungus) obtain energy from glucose (sugar) by a specific anaerobic process called fermentation. There are two types of fermentation, lactic acid fermentation (which occurs in muscle cells when they are oxygen deprived), and alcoholic fermentation, which is involved in the making of food products. Alcoholic fermentation begins after glucose diffuses into the yeast cell. The glucose is broken down into 2, 3 carbonmolecules called pyruvic acid. The pyruvic acid is then converted to CO2, ethanol, and energy for the yeast cell. Don't get excited, students, there is very little ethanol in this root beer. :)
Fermentation is used to make a variety of food products, including the making of beer, wine, bread, cheese, sauerkraut, and baked goods. It is the carbon dioxide produced by the yeasts that give root beer its "fizz." This fizz is produced in store bought root beer by a carbonation machine that forces carbon dioxide into the root beer mixture, without the aid of our little yeast friends.
Equation for alcoholic fermentation:
C6H12O6 ------> 2 CO2 + 2 CH3CH2OH (ethanol) + 2 ATP

Analysis Questions:
Questions with ** should be answered the day root beer is made. All others should be answered when the root beer is ready.
1.** Describe the appearance of the root beer during the bottling process.
2. Describe the appearance of the root beer after fermentation. How is it different?
3.** Why were the yeasts necessary in this experiment?
4.** Why was the sugar necessary?
5. Explain how the root beer came to be carbonated.
6.** Explain how commercial (store bought) root beer is carbonated.
7.** What is safrole? Why do we not use it anymore?
8. **List the needed ingredients to make root beer.
9. Why did we put the yeasts in the warm water for 5 minutes?
10.** What is fermentation?