The Chemistry of Diet Coke

IntroductionDiet Coke is a popular, calorie free soft drink. It is a modified version of the original Coca Cola. It first appeared on store shelves in 1982. There are many different variations of Diet coke such as, caffeine free, lemon, lime, raspberry, black cherry vanilla, sweetened with Splenda, and Diet Coke plus. In other countries there are different variants of Diet Coke too. Diet Coke may taste different in different countries. I chose to research the chemistry of Diet Coke because it is my favorite type of soda. I am curious about how it is made, and what the ingredients are that it is really made with. My life is affected by diet coke because I drink it at least once a week. Many Americans drink multiple cans of Diet Coke each day too. The average American consumes about forty gallons of soda each year. Since 1978, soda consumption in the us has tripled for boys and doubled for girls.

Composition of ...

    • Carbonated Water
  • High Fructose Corn Syrup
  • Caramel Color
  • Phosphoric Acid
  • Natural Flavors
  • Caffeine
  • Aspartame (NutraSweet)
  • Potassium Benzoate
  • Citric acid

Main Chemicals, Compounds, Components

    • The two main components are carbonated water and caramel color.
    • Molecular formula for carbonated water is, H2CO3
    • Molecular formula for caramel color is, C18H9N Na2O8S2
    • Carbonated water is water that contains carbon dioxide gas. The gas causes there to be small bubbles in the water.
    • Caramel color is the most consumed food coloring ingredient in the world. It results from controlled heat treatments of carbohydrates.

Chemistry's Role

Carbonated water is usually artificially produced by pressuring carbon dioxide into water at the bottling plant. If one wants to make carbonated water at home, they can buy seltzer bottles as well as soda chargers. Carbonated water is man made, not naturally occurring. Chemistry processes are used to make carbonated water.

Caramel Color is made by a carefully controlled heat treatment of carbohydrates, generally in the presence of acids, alkalis, or salts, in a process called caramelization. It is more fully oxidized than caramel candy. It is man made, not naturally occurring. Chemistry processes are used to make caramel color.

Background Research

  • Instead of sugar, Diet Coke contains artificial sweeteners
  • Each Can of Diet Coke has less then one calorie
  • Up 94% of the drink is made up from carbonated water
  • Diet Coke was first introduced in the United States on August 9, 1982
  • How Diet Coke is made: All impurities must be removed from the water that goes into the drink. The impurities are removed through different processes, such as, coagulation, filtration, and chlorination. Coagulation involves mixing a gelatinous precipitate. When the water is filtered it is poured through a sand filter to remove fine particles of floc, or or ferric sulphate aluminum sulphate. After the water is purified, the next step is mixing the different ingredients together. After the ingredients are mixed the drink is carbonated, and then put into bottles or cans. For a more detailed explanation of how Diet Coke is made visit
  • Aspartame has been linked to causes of cancer
  • Because Diet Coke is so acidic, it leeches the body of essential minerals. For example, iodine is a key mineral for the thyroid to function. A job of the thyroid is to regulate metabolism. If the thyroid does not produce, metabolisms usually slow down, causing weight gain.


-Ingredients in Diet Coke and Nutritional

-More facts about ingredients and nutrition

-Many Links

-History of soft drinks

-Different facts

-Explains how it is made

-Statistics and facts about the dangers of soda

-Statistics and facts about the dangers of soda

-Information about Diet Coke and the different types of Diet Coke

-Ingredients picture

-What is carbonated water

-What is caramel color

-How carbonated water is made

-How caramel color is made

-Caramel color formula

-Carbonated water formula

About the Author

Annelise Grygiel is currently a junior in high school at Billings Senior High. She runs cross country, plays the cello, horseback rides, and is an avid hockey fan. Annelise is also a member of Senior Advocates, Trading Cards, National Honors Society, and Key Club. She hopes to end up somewhere in Colorado for college once she graduates from high school.