We’ve been covering matter in the lower grade classroom for a while now…solids, liquids, gases etc. This last week we started talking about physical changes. A physical change is where something changes its shape, size, or appearance, but the matter itself doesn’t change. Of course, the book gives the example of folding paper…or ripping paper…or crumpling paper. What fun. So, instead, I decided to add a cooking element to this science concept.
We made butter.
In case you have never made butter, it’s pretty easy.
First, get a group of excitable and energetic children together.
Second, take a pint of heavy whipping cream, place it into a tupperware container.
(Add salt if desired)
Third, shake. I recommend each kiddo take 30 second shifts at shaking. On Thursday, I separated the boys from the girls in a shaking competition.*
*Interestingly, the boys pretty much had butter after ten minutes. They took their shaking seriously. The girls supported each other and had a lovely time. The boys were shouting, “SHAKE HARDER!” It was intense. There was some leakage and sore arms on the boys side. Meanwhile the girls politely handed the container one to another. Gentle shakes and smiles were had. I am wondering why women were the butter churners in the old days. Men would have had this chore done in no time flat.
After 10 or 15 minutes, the cream has become butter! How does this happen?
Well, the fat in the cream is like a tiny little balloon filled with sticky fatty molecules on the insides. After you shake it long enough, the “skin” of the fat blobs ruptures. The sticky insides then come out. The fat starts to clump together, separating from the water that is also in the cream. The more you shake, the more the fat clumps together.
SHAZAAM! Butter. (Also Buttermilk…which is the nasty liquid at the bottom of the container.)
Now of course, I didn’t explain that to a group of 5-7 year olds, but I did explain that it was still cream, and that we had just seen a physical change. Good times.
Well, we had a good time making the butter, but I didn’t bring bread to eat it with. So, on Tuesday, we got our butter out of the fridge and had a delightful and education filled afternoon snack. Interestingly, one kid asked if bread was a physical change…which its not. It’s a chemical change.
So now I’m on my Christmas break. What does my son want to do? Make butter…he tried today with milk. Tomorrow we shall get cream and do it for real.
So, scientific readers, any food science ideas you’d like to share?