Doing the Milk Dance

A couple of days ago, I watched a video titled "Dancing Milk" for my honors bio class. http://www.youtube.com/watch?v=_oC1FlJBsVA After watching this video, I came up with a hypothesis as to why the milk and food coloring interacted the way they did. Soap is a type of degreaser; therefore, the dish soap is attacking the fat in the milk. My partner also brought up a good point about how the dish soap is a base, so it reacts with the acid, or the milk.

In order to prove both of our hypotheses, we created two experiments. For my hypothesis, we used coffee mate creamer, which, like the milk, contains fat. We poured 10 mL of creamer into a small plate. Next, we added a few drops of red and green food coloring. Then came time for the dish soap. My partner and I first used a diluted dish soap and the reaction looked similar to the reaction with the milk in the video. However, we then added a concentrated dish soap, and as soon as we did a clear bubble formed in the middle of the colored milk.  

We did this exact procedure two more times and continued getting the same results...

When we finished with this experiment, my partner and I decided to move on to her acid-base reaction hypothesis. This time we used vinegar as our acid and, similar to our other experiment, we used 10 mL. Just as before, we added a few drops of green and red food coloring, plus a drop of dish soap. The reaction was not as we expected. Though the color did seem to dance at first, they did not move the same way they did with the milk and creamer. We did this experiment two more times, and nothing really happened. There was no bubble formed and the movement was not the same.

My partner and I were expecting both the creamer and the vinegar to react similarly to how the milk reacted with dish soap. However, we were proven wrong and only the creamer reacted in a similar manner. So, my hypothesis about the degreaser (the dish soap) attacking the fat in the milk and being the cause of the food coloring's interaction with the milk was indeed correct.