Darker Chocolate = Higher Specific Heat Capacity

Not surprisingly, I discovered that the darker the chocolate (high percentage of cocoa), the higher the specific heat capacity. This means it takes more time and more energy to melt the same quantity of chocolate if it is 90% cocoa versus if it is 50% cocoa.

Average temperature change of 50% chocolate:  = 42.7°C

Specific Heat Capacity = 4.15J/g°C

Average temperature change of 70% chocolate:  = 40.3°C

Specific Heat Capacity = 4.39J/g°C

Average temperature change of 85% chocolate:  = 38.6°C

Specific Heat Capacity = 4.59J/g°C

Average temperature change of 90% chocolate:  = 33.5°C

Specific Heat Capacity = 5.28J/g°C

As you can see from the data I collected, darker chocolate increases less in temperature, hence it has a higher specific heat capacity. 

I don't know if this information is particularly useful for home bakers, but maybe some professionals use it, especially in commercial chocolate-making and similar goodies. It is not common knowledge (I tried an internet search and found no solid answers). However, it may be helpful to know that "lighter" chocolate takes less heat and less time to melt - so watch it carefully, and expect to wait a bit longer for your dark chocolate to melt. This may be most helpful in making ganache, fondue, and candies. It would be interesting to see if other factors come into play. For example, what about milk chocolate and white chocolate? How high are those specific heat capacities? That'll be another experiment for another time...

A big thanks to my father for all of his help with this experiment!