Sherbet Punch! (And the secret of a root beer float)

Again for my friend's baby shower I found a fun punch to make that looks like a bubble bath! This punch works like a root beer float, and when you add the sherbet it foams and tasts fabulous.

1 Pkg Blue Typhoon Hawaiian Punch
2 L of Ginger Ale
62 oz of White Grape Juice
8 Scoops of Pineapple Sherbet
+
Garnish! I used rubber duckies, while not eatable, they were really cute.

1. Chill the Ginger Ale and Grape juice.
2. Softened Sherbet. I recommend NOT using a microwave 
3. Mix Hawaiian punch and grape juice
4. Add Ginger Ale
5. Float scoops of ice cream on the top of the punch!


The Chemistry!


This punch works with similar principles to a Root Beer Float! It may surprise you to find out that there is no "chemical" reaction in a root beet float. (Or in our case, a rubber ducky Sherbet punch). It is in fact a "physical reaction." Ginger ale, root beer, and other sodas have liquid carbon dioxide mixed with water. It is the CO2 (Carbon Dioxide) that makes them fizzy. The surface tension of the water "holds" the CO2 in liquid form by resisting the transition of liquid to gas.

This surface tension is one of the most unique features of the liquid water. Because water is such a prevalent liquid we don't get much of a chance to observe other liquids and the LACK of surface tension. The H2O molecule is one Oxygen bonded to two hydrogens. The bonds between the oxygen and hydrogen is very strong, and forms a 105 degree angle.

Because of this angle the overall molecule will form a polarity. Where the Oxygen is slightly negative and the hydrogens are slightly positive. The slightly negative oxygen will be attracted to the slightly positive hydrogen of another water molecule. Thus creating another "bond" between water molecules, often referred to as a "hydrogen bond." The hydrogen bond is not as strong as the molecular bond of water, but it can be very strong in chemical reactions. It is this bond between molecules that creates the effect of surface tension. One way to think of these inter-molecular bonds is as a very tight net.

To release the CO2 from the surface tension of the water, we need to interrupt the net. Think about your soda, if you shake it up what happens? The CO2 will escape rapidly and you can have a mildly explosive reaction on your hands. I don't recommended it. It isn't difficult to interrupt the surface tension of water, all it takes is a physical interruption. Think about why you want to point your toes when you are cliff diving, rather than land flat on your belly. It is easier to break a "net" with your feet that your belly. Your tongue does something similar to soda. The rough surface of your tongue interrupts the surface tension of the soda, releasing the CO2 and you are left with a fizzy sensation.

Ice cream will lower the surface tension of root beer in two different ways. #1- The rough surface of the ice cream provides, many areas for nucleation of the CO2 into gas. #2- Protein in ice cream lowers the surface tension of water. Thus releasing the gas in the punch and forming a foam that is easily the BEST part of a shertbet float!

And that is how it works!