Research Question: Will the temperature of sugar solution affect the performance (Making foam) of yeast? Hypothesis: If the temperature of sugar is higher, yeast will perform more immensely. Background research: Differences of temperature of yeast doesn’t make any effects but differences of temperature of sugar solution makes the yeast to perform quicker. Independent Variable: - Temperature of sugar solution Dependent Variable: - The height of foam made by the performance of yeast Control Variable: - Amount of sugar solution - Amount of yeast - Concentration of sugar solution - Type of yeast - Type of sugar molten in the solution Materials: - Three 100ml Cylinder - 285ml of Water - 15g of Sugar - 6g of Yeast - Timer - Thermometer - Heater - Three 100ml beaker - Electronic balance - Funnel - Scrap paper - Pen Procedure: 1. Put 55ml of water in each cylinder 2. Measure 5g of sugar with the electronic balance 3. Repeat the above action three times 4. Put them in the cylinder with the 55ml of water 5. Mix the solution 6. Measure 2g of yeast with the electronic balance 7. Repeat the above action three times 8. Shake the solution 9. Boil 3 of 40ml of water in the temperature of 45°C, 50°C, 55°C 10. Put them in each solution and write the temperatures on the scrap paper and put them next to the ones that match 11. Use timer and wait for 20 minutes. 12. Measure how much foam the solution had created. 13. Compare the foams from each temperature. Data/observation Sugar solution mixed with 45°C Sugar solution mixed with 50°C Sugar solution mixed with 55°C 5 minute later 10 minute later 13 minute later 113ml 128ml 134ml 123ml 126ml 132ml 102ml 106ml 112ml If the water solution went over 55°C, the reaction of yeast was not strong. The reaction of yeast was stronger as the temperature goes up but if the temperature went over 50°C, the reaction didn’t happen as much as in lower temperature. 5 minute later 10 minute later 13 minute later Conclusion From my background research, it showed me that the yeast reaction doesn’t happen if the temperature is upper than 40°C. However, my sugar solution isn’t purely 45°C, 50°C and 55°C but I put 40ml of boiled water that has each temperature into the solution, so we can assume that the solution mixed with 55°C water has about 40°C. Unless the solution has temperature upper than 40°C, the reaction of yeast reacts more in higher temperature. My hypothesis was right, but I didn’t know that higher than 40°C temperature blocks the reaction of the yeast. Evaluation I struggled a lot throughout the experiment. In my first experiment, I misunderstand the strength of the reaction of yeast. I used a lot of yeast in the solution so that the reaction was too strong which led the it to explode. I decided to use 20g of yeast in the experiment instead of 40g which led the explosion. My independent variable’s scale was not detailed enough. I only conducted research in three different temperatures which didn’t give a detailed result. My sugar solution wasn’t exactly 45°C, 50°C and 55°C. Not only they cooled down, but I also forgot to measure the temperature of sugar solution before I put yeast. I put 40ml of boiled water in each temperature instead. My measurements weren’t accurate. Since I used cylinders that has the numbers only up to 100ml, I couldn’t measure it properly. I should use bigger cylinder next time. I couldn’t put the boiled water at the same time which led the inaccurate temperature.
