In the production of chocolate, the natural fat in cacao beans (called cocoa butter) is removed, leaving cocoa powder behind. The cocoa butter is then added back into the cocoa to create smooth, creamy chocolate. How important is it to add cocoa butter into the chocolate? What effect does it have on the texture and the melting point of the chocolate? Do this project to find out.
What You Need:
- Unsweetened cocoa powder
- Unsweetened chocolate chips
- Three bowls
- Wax paper
What You Do:
- In the first bowl mix some cocoa powder with a little water to make a moist paste. In the second bowl mix cocoa powder with a little melted butter, and in the third bowl melt a few chocolate chips.
- Observe the texture of each mixture. Which one looks the smoothest? The shiniest? Spread some of the contents of each bowl on a piece of wax paper and wait for them to solidify. Do they harden at the same rate? (You can speed up the hardening process with refrigeration, but check every 5 minutes to observe the difference between them.)
- Feel each sample - are their textures similar? Try breaking a piece off; how does it break? (If you're very brave, try a test taste; but you may be surprised at the taste of unsweetened chocolate!)
- Put a little of the chocolate from the second and third bowl in the palm of your hand. Which one begins to melt first? Do they both melt smoothly and evenly?
Cocoa butter is a necessary ingredient to give chocolate the texture we all love. Unlike other plant-based fats, such as olive oil, cocoa butter is solid at room temperature, but melts quickly at just under body temperature--when you put it in your mouth, for instance. Cocoa powder has some cocoa butter in it, but not enough to make it harden like solid chocolate. Butter is an animal fat made from milk that will behave differently from cocoa butter. You will notice that its texture is very different from the melted chocolate chips, which are made with cocoa butter. If you can access regular cocoa butter (perhaps at a health food store), try this project again adding melted cocoa butter to cocoa powder instead of using chocolate chips.
Different kinds of chocolate will have different melting points, depending on what ingredients are in them. Try another project comparing the melting point of dark chocolate, milk chocolate, and white chocolate.