Milk…yum! Butter…even better!
The past couple of weeks my G3 crew and I revisited a really fun program that lets us play with some basic ingredients from the food store. And, as a bonus, I added a yummy component to the day’s activities – making our own butter!
EXPERIMENT #1: Let’s Make Butter!
- Heavy whipping cream (room temperature – out of the fridge for 6-8 hours)
- Small jars with secure lids (I used recycled 4 oz. baby food jars, one for each scientist)
- A little salt for flavoring
- Bread, for snacking
I recently stumbled across a youtube video where a man was making his own butter with his own two hands in a very simple process. So simple, in fact, that I was amazed I had never heard of the process before. And interestingly, none of my G3 scientists had ever done this experiment either! So, I told my crew that our first challenge for the day was for each of us to make our own butter…so we could have a tasty after-school snack!
I passed out the jars, which had about 1/4 to 1/2 inch of heavy cream in the bottom. [This small amount of cream produces plenty of butter for each individual scientist, approximately 1-2 servings.] I instructed my scientists to add a pinch of salt for flavoring (most of us eat salted butter at the dinner table). We sealed the jars tight, and then it was just a question of some time and arm muscle. You need to shake the cream in the jar for about 10-15 minutes to instigate the physical change in the cream. Basically, when you agitate the cream for a long enough period of time, you are helping to separate the fat solids from the “butter milk.” [NOTE: Leaving the cream at room temperature for a while helps the physical transformation along at a quicker rate.] Our group actually did not get to the stage where the solid fat and butter milk truly separate – our results were more of a whipped butter quality. However, that did nothing to impact the taste! I passed out some bread so that every scientist could taste their own butter creations. All agreed that it was very yummy 🙂
The second part of our program was all about MILK.
Milk is a beverage that most of us drink every single day, but probably not one that we give much thought to. Some of us drink cow’s milk. Others of us (myself included) drink other varieties of milk, like almond milk or rice milk. Because I just can’t help myself when it comes to sharing ‘fun facts,’ here’s a highlight of some information I shared with the group at the start of our program:
- The habit of drinking milk actually became popular over 10,000 years ago when animals were first domesticated in Afghanistan and Iran. Domestic cows – where we get most of our milk – didn’t even arrive in North America until the 1600’s!
- Cows produce 90% of the world’s milk needs, and an average cow can produce the equivalent of about 90 glasses of milk a day (or 200,000 glasses during its lifetime).
- But Cows aren’t the only animals that produce the milk and dairy products that humans consume. You can add to that list goats, sheep, apes, yaks, water buffalo, reindeer, and horses!
- Why do our dentists say that milk is good for our teeth? Milk and dairy products actually reduce the amount of acidity in our mouths, curb plaque formation, and even reduce the risk of cavities.
As scientists, though, we want to know what exactly milk is…so we can figure out some fun ways to experiment with it. Think of milk as a solution of mostly water that also contains vitamins, minerals, proteins, and fat “droplets.” The proteins and fats actually float around freely in the solution. The gotmilk website actually has some very fun online games that show you just how difficult it is to create a substitute beverage for milk.
Our mission for the ‘got milk’ experiments was a simple one: What happens when you add food color drops to milk, and then introduce a drop of regular dish washing soap?
EXPERIMENT #2: Colorful Milk
- Milk (I only used whole milk this time around, but when we did this experiment in the past I had our scientists test various kinds of milk – including skim, 1% and 2%)
- Liquid food coloring (NOT the gel food coloring that is popular in stores today – I actually discovered the liquid food colors shelved with the spices at the food store)
- Plastic or coated plates (the first time around we used coated paper plates, but over time even they get rather droopy, so this time we used plastic plates)
- Liquid dish soap (any variety – I used Dawn brand soap)
- Small Dixie or bathroom cups to put the soap in
- Paper towels for any mess
We poured just enough milk into our plates to completely cover the bottom of the plate. Each scientist determined which colors to add to the milk solution. Only 1 or 2 drops of food coloring per color is necessary, but some of our scientists wanted to add more in specific patterns throughout their plates of milk. Once the drops of food coloring were in place, we dipped a standard q-tip into the Dawn soap, and then slowly lowered it into the center of the plate of milk (you don’t have to put the q-tip into the color drops themselves). What were the results?
The results were both instantaneous and VERY COOL. With just a single drop of dish soap, the colors instantly begin to swirl around the milk in crazy patterns. But why does this happen? Well, remember from our description of the milk solution that the fat droplets are actually floating around in the main solution of the milk. The dish soap molecules are designed to instantly want to attach themselves to fat molecules. [That’s why dish soap does such a good job of cleaning up greasy pots and pans!] As the soap molecules race around the solution trying to attach to the floating fat droplets, the food coloring molecules are frantically pushed around the plate. Hence, the crazy swirling of colors that the G3 scientists witnessed!
What would happen if you tested this with other liquids/beverages? This is a simple experiment that can be done at home. Just be careful with the food coloring since it will stain just about any material. You can also read more about this experiment by looking at the “Color Changing Milk” experiment on Steve Spangler’s web site.