In my previous posts on how to teach science at breakfast we focused on how the concepts of atoms, density, diffusion, and the Law of Conservation can be found during the first meal of the day. We’ll return to a couple of these concepts throughout this post, but I think it’s time to look at something a little different. For example, in my last post I hinted at my recipe for pancakes:
“…a little flour, an egg, some milk, a small amount oil and sugar, and a few pinches of baking powder and salt…”
We talked a little about the science within the sugar and flour, but many questions were left behind. For example:
What exactly IS baking powder?
Well, baking powder is collection of different kinds of molecules (groups of atoms). Whatever brand of baking powder you have in your kitchen, they ALL contain the same combination of molecules:
Molecule #1 – A dried acid (possibly Cream of Tartar – which is known to us scientists as Tartaric Acid)
Molecule #2 – A base known as sodium bicarbonate (also known as Baking Soda)
Both baking soda AND baking powder can usually be found in your kitchen cabinet. But as you just learned, they are definitely not the same. Each product contains different molecules and have different properties. For example:
What does the acid in baking powder do?
To answer that question, you have to understand what happens when you mix together a base (like baking soda) with an acid (like Cream of Tartar.) When these two molecules are dry, they cannot react with each other very well.
However… If you dissolve these solids in a liquid, all these atoms REALLY start to move around!
You see, whenever you mix acids and bases together, their atoms start to break apart from each other and rearrange into new molecules! This is exactly what the Law of Conservation states – atoms cannot be created or destroyed, only rearranged.
When you mix a fluid like water with baking powder, the new molecules that are formed are in the form of a gas called carbon dioxide. These molecules form very quickly in your pancake batter.
I’d guess that most of us have attempted to make the famous “Volcano Eruption” either at home or school… Mix together a little vinegar (acetic acid) and baking soda and you get a fast-moving bubbly mess! This is the same reaction that is taking place within your pancake batter. The only difference is the type of acid that is being used.
Since we are on this topic, I’d like to apologize to my mother once again for all of the “kitchen experiments” in my childhood that taught me how messy science can be. Love you Mom! Feel free to send me the cleaning bill. I think I can afford it now!
So gas is being produced when I mix together a pancake batter?
You bet it is! In fact, it is a good idea to mix together your ingredients within the pancake batter (gently), and let it rest for a few minutes before you start to cook.
But I’m hungry and the batter is ready! Why should I wait???
By waiting a few minutes, the acids and bases within the baking powder start to dissolve within the batter and react with each other. This produces millions of tiny bubbles (carbon dioxide) into your batter which will help your pancakes be nice and fluffy!
So what else can be done to keep my pancake from looking and feeling like a hockey puck?
Well, the oil you add to your batter keeps your pancake from getting too firm AND all that sugar isn’t only to satisfy your sweet tooth. Sugar has a good way of absorbing liquids which keeps your batter nice and moist.
There’s another trick to keeping your pancake fluffy. I mentioned it earlier in the post when I suggested that you GENTLY mix together your batter. Why shouldn’t you put your pancake batter in a blender for awhile? The answer to THAT question is hidden inside the chemistry of flour which we will be looking at next week. Stay tuned…
Find out more about scientific concepts for your family within the Classic Science Curriculum
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