Experimental Design

Does More Yeast mean More Fizz?



            You’ve heard people talk about trying to make soda more fizzy. Well, there is a way to do this. Using yeast increases the CO2 concentration within a soda, which causes the soda become more fizzy because of all the CO2 it has. This keeps the soda remain carbonated and doesn’t go flat. Sodas kept in cold temperatures keep the CO2 concentration in its place so that it prevents the soda from going flat. With more CO2, that means more fizz.

            Yeast is used as a fermenting agent in the Ginger Ale. It consumes the sugar that is inside the drink and creates more carbon dioxide. After the yeast is put inside the drink, this could take about 3-5 days for the yeast to have fully carbonated the drink. We used two bottles to make our Ginger Ale and put in different amounts of yeast. For Container 1, we put in ½ teaspoons of yeast while Container 2, we only put in ¼ teaspoons of the yeast, the usual amount after putting in the rest of the ingredients to make the soda. After this was done, we began shaking the bottle long enough and stored both of them in the fridge for about 5 days, so that the drinks stay carbonated and don’t go flat. What is happening in the drink is; the yeast is consuming the sugar that is inside the sodas and is creating more carbon dioxide due to the fermentation process. When it's kept in the fridge, the carbon dioxide stays in the soda and due to the cold temperatures, it’s difficult for the carbon dioxide to escape the soda, therefore it remains inside the drink keeping it carbonated. After 5 days has passed, we measured the solubility of both drinks. When we opened Container 1, it released a lot of fizz. When we measure it, it came out to 260,000 ppm of CO2 concentration. Container 2 didn’t fizz as much as Container 1 and had only 240,000 ppm. 

            To conclude, Yeast increases the solubility of soda. It consumes the sugar in the soda and creates more CO2 which increases the solubility of the drink. This explains how yeast causes an increase in carbonation. Container 1 had more yeast and when the bottle was opened, a lot of fizz spilled out which mean a lot of carbon dioxide espcaped, the container couldn't hold it all in, this shows that more yeast had created more carbonation, to the point where CO2 desparately wanted to escape the container. It's concentration ended at 260,000 ppm. Container 2 had 240,000 ppm since it had less yeast, which meant less CO2 was inside. This showed that more yeast results in more CO2 which increases the overall solubility of a soda. 





 What makes soda taste fizzy? Why does soda become flat? Why can't soda stay fizzy in warm temperatures? How can you make soda even more fizzier?

Science Sidebar

Solubility is the amount of a substance that will dissolve in a given amount in a liquid, in this case, ginger ale. The solubility is affected by the change in the temperature and pressure. In the making of ginger ale, when we put in yeast, it creates CO2 inside the soda when consuming the sugar. This causes the soda to become carbonated. The amount of yeast has a change on the CO2 levels because with more yeast, it consumes more sugar and creates more CO2 which affects the solubility, making it greater.

          Along that, to make it stay carbonated and to become more fizzy, you would have to keep the temperature low and increase the pressure. This is done because you need to keep the temperature low so that the CO2 movement is decreased which leads it to have a more difficult time escaping. Increasing pressure is what leads to the decrease of temperature which prevents the CO2 from escaping. Keeping the temperature low is done by storing the ginger ale in the fridge. It was kept for five days so the drink remained carbonated.