In 2015, I did an EEI on the fastest way to cool a drink – a fridge, freezer, ice cubes, an ice bath, and an ice bath with salt. The PDF is available here: fastest-way-to-cool-a-drink.
The abstract and key results are below:
This experiment studied the effectiveness of five different methods of cooling a cup of water. The time taken for each method to cool 100 g of water from 23°C to 10°C was measured, with the temperature of the water being recorded at regular time intervals so a graph of temperature against time could be produced. The cooling devices tested were: a fridge, a freezer, ice cubes, an ice bath, and an ice bath with salt added. The saline ice bath was found to be the most rapid method of cooling the water, taking only 8 minutes. The ice bath and freezer were moderately effective; however the fridge and ice cubes were considerably slower. Because the saline ice bath used both conduction and convection to transfer heat, it was concluded that heat transfer using both these processes was faster than heat transfer using convection or conduction alone. Furthermore, it was also concluded that when all other variables are kept constant, the rate of heat transfer is proportional to the temperature gradient.
The fastest way to cool a drink was the ice bath with salt added (average time of 7.9 minutes to cool 100 mL of water from 23°C to 10°C), and the slowest was the fridge (average time 68.3 minutes).