Thursday, May 08, 2014

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!

7 comments:

Anonymous said...

How did you calculate this and what procedures did you take?

Bexy said...

Hello, I am glad to see you show an interest in my food-related experiment!
It was actually an open high school physics project meant to be based around students' interests. If you would like, I can send you the entire report detailing procedures, variables, and calculations.
Also, if you haven't already, be sure to check out the related posts: http://bexysbakingblog.blogspot.ca/2014/05/specific-heat-capacity-of-chocolate.html and http://bexysbakingblog.blogspot.ca/2014/05/7375-cocoa-fudge-brownies.html.
Thanks for reading! :)

Brad Menezes said...

hello, do you mind sending me your report? im doing something similar for school and would really appreciate your help :)

Bexy said...

Sure! I presume you will be listing my blog site in your list of sources then. What is your email address and I will send it to you?

Akanksha Shah said...

Hello Becky,

I too am looking at the specific heat capacity of chocolate for an independent investigation at school. I am however, looking at the effect of percentage fat in milk on the specific heat capacity. I have been trying to find resources but I haven't been very successful, until your blog. Could you also share a copy of your report with me please? (it would be of great help)

Bexy said...

Your investigation sounds very interesting! These types of projects are very fun to do. Please provide me with your email address and I will send along the report to you. And please let me know what you discover with the results of your report!

Akanksha Shah said...

Here is my email: akanksha24shah@gmail.com.