Fried Green Egg Food Science Project

Use Red Cabbage Juice to Make an Egg White Turn Green

Use a color-change pH indicator made from cabbage to turn an egg white green for St. Patrick's Day or any day you want green eggs and ham.
Use a color-change pH indicator made from cabbage to turn an egg white green for St. Patrick's Day or any day you want green eggs and ham. Steve Cicero, Getty Images

Red cabbage juice contains a natural pH indicator that changes color from purple to green under basic (alkaline) conditions. You can use this reaction to make a fried green egg. This a great chemistry project for St. Patrick's Day (March 17th) or to make green eggs and ham for Dr. Seuss's birthday (March 2nd). Or, you can just make green eggs to gross out your family. It's all good.

Green Egg Materials

You only need two basic ingredients for this easy food science project:

  • egg
  • red (purple) cabbage

Prepare the Red Cabbage pH Indicator

There are several ways you can prepare red cabbage juice for use as a pH indicator. Here's what I did:

  1. Coarsely chop about a half cup of red cabbage.

     

  2. Microwave the cabbage until it is soft. This took me about 4 minutes.

     

  3. Allow the cabbage to cool. You may wish to set it in a refrigerator to speed things up.

     

  4. Wrap the cabbage in a coffee filter or paper towel and squeeze the cabbage. Collect the juice in a cup.

     

  5. You can refrigerate or freeze leftover juice for later experiments.

Fry a Green Egg

  1. Spray a pan with cooking spray. Heat the pan over medium-high heat.

     

  2. Crack an egg and separate the egg white from the yolk. Set the yolk aside.

     

  3. In a small bowl, mix the egg white with a small amount of red cabbage juice. Did you see the color change? If you mix the egg white and red cabbage juice thoroughly then the 'white' of the fried egg will be uniformly green. If you only lightly mix the ingredients you will end up with a green egg that has white splotches. Yummy!

     

  1. Add the egg white mixture to the hot pan. Set the egg yolk in the middle of the egg. Fry it and eat it like you would any other egg. Note the cabbage does flavor the egg. It's not necessarily bad, just not what you expect eggs to taste like.

How It Works

The pigments in red cabbage are called anthocyanins.

Anthocyanins change color in response to changes in acidity or pH. Red cabbage juice is purplish-red under acidic conditions, but changes to a blue-green color under alkaline conditions. Egg whites are alkaline (pH ~9) so when you mix the red cabbage juice into the egg white the pigment changes color. The pH does not change as the egg is cooked so the color is stable. It's also edible, so you can eat the fried green egg!