Monday, July 21, 2014

Summer Fun 2014 - Root Beer Floats - Experimenting With Nucleation

We had both diet, and regular root beer left over from a buoyancy/density test, for a sink or float experiment, to meet the final requirement on our library's science themed summer reading list...

...and Sunday just happened to be National Ice Cream Day.  It only seemed fitting to set up a summer, Sunday science, snactivity with root beer floats for everyone - including a few neighborhood friends who came running, when I called my own inside. 

First we talked about nucleation - the process of the carbon dioxide bubbles getting stuck in the craggy, oxygen bubble covered surface of the ice cream, where they sit pulling in more, and more bubbles, becoming larger and larger, creating a frothy, delicious, fat coated foam.  Then, I turned the children loose to experiment.

We made some floats by:
  • dropping ice cream into the root beer,
  • pouring root beer over small scoops of ice cream,
  • pouring root beer onto ice cream, that had been pressed, and smoothed as much as possible into the bottom of the cup
  •  and pouring root beer onto melted ice cream - which made a wonderful root beer fizz.

We used vanilla ice cream and:
  • warm regular root beer,
  • cold regular root beer,
  • warm and cold diet root beer,
  • and cold Coke Zero...

...observing the levels and quality of foam, and being delighted to find ice crystals forming in the root beer left to sit on top of the ice cream.  Some of our soda sat for a while before we got around to adding ice cream, and just as you might imagine, the foam was nearly as flat as the soda.

Then, just to be sure we were observing a physical change and not a chemical one brought on by combining ice cream and soda, we added some root beer to plain milk.

That brought our experiments to an end, as we switched over to a discussion of Laverne and Shirley, and Laverne's love of milk and Pepsi, and how I always wondered what that would taste like.  

If it's anything like root beer and milk, I wouldn't recommend it.

Resources we found handy:

How an Ice cream Soda or Float Works from,
Kitchen Chemistry from,
Fizzics from The Fizz,
and Why is There So Much Foam in a Root Beer Float?  from Wonderopolis.


claireshomeeducation said...

Y'know I've never tasted root beer (what is it exactly?) and I have never had any kind of ice cream float. It sounds a bit revolting but Gary has just leant over and told me they're lovely. Who knew?!

Natalie PlanetSmarty said...

You always have the best, tastiest science imaginable :) Recently my daughter tasted a root beer float for the first time and declared it "yuck". I suppose it's like root beer and milk to her :)

An Almost Unschooling Mom said...

Claire - Never had a root beer!?! It's somewhere between a cream soda and a cola. It's the pop most people give to children (if they let them have pop) because it doesn't have caffeine. Root beer floats are "lovely", at least I think so - but not good for weight loss :)

Ai said...

I can't believe I missed National Ice Cream Day. Well, I take that back. We've been celebrating the last couple of weeks now.

Dawn said...

I can't believe Claire has never had a root beer float! She really must fix that situation. As for your fun day! I wish I lived in you homeschool.
Blessings, Dawn

Ticia said...

I'm betting that would be a science experiment that had my kids very very happy.

Kim said...

This looks like a fun experiment (as with so much on your blog). When we got our Soda Stream (carbonator) one of my boys carbonated a bottle of milk. I thought it might taste something like an ice cream soda, but no. It was horrible--possibly worse than root beer + milk.