1. Write down a hypothesis of the effect of temperature on the rate of decay of milk
2. Carefully, fill half of a beaker with hot water (60℃ or below) from the kettle for a water bath
3. Use a syringe to transfer 5 cm³ of lipase solution into a boiling tube and label as 'lipase'
4. Add 5 drops of Cresol red into another boiling tube and label as 'milk'
5. Use a calibrated pipette to transfer 5 cm³ milk into the 'milk' tube
6. Use another calibrated pipette to transfer 7 cm³ sodium carbonate solution to the 'milk' tube, which should make a purple solution
7. Place a thermometer into the 'milk' tube
8. Place both boiling tubes into the water bath
9. Allow time for the solutions in the boiling tubes to reach the same temperature as the water bath
10. Use another pipette to transfer 1 cm³ of lipase from the 'lipase' tube into the 'milk' tube and start timing immediately
11. Record the time required for the colour change to yellow in a table
12. Repeat steps 2-11 at the same temperature twice and take a mean value
13. Repeat steps 2-11 using a range of different temperatures of water baths (a range from 20℃ - 60℃)
14. Plot a graph of time taken against temperature
