This is one of my favorite birthday party tricks! I think it is so cool, and kids think it’s pretty cool, too. Who doesn’t love magic, especially when it involves food? I set up this magical, color-changing punch at a recent My Little Ponies theme birthday party. I prepared everything and Birthday Girl got to be the magician and impress all her friends by turning some blue punch into pink punch. Birthday Girl had a blast making magic, and all the other kids were in awe of her color-changing skills. The best part of this food magic is that it is all natural. No artificial colors or food dyes here. The first secret to this magic trick is purple cabbage. Yep! Purple cabbage turns water blue. The second secret? Lemons! Acid turns purple cabbage pink.
Okay so let’s break it down. This isn’t really magic at all, it is science! Science is pretty stinkin’ cool, and food science is even cooler. Purple cabbage is purple because of something called flavenoids (the more science-y name is Anthocyanin). These flavenoids are molecules that turn plants purple, red, pink, and just about any color in that spectrum. They are responsible for some leaves turning from green to red in the fall! You can also find purple cauliflower at fancy stores and farmer’s markets, and guess what? That purple cauliflower is purple for the same reason as purple cabbage. That’s right: anthocyanins! See? Isn’t science fun?!
Anthocyanins are affected by acids in the environment. We can force this interaction by purposely introducing an acid to the purple plant. In this case, our acid is lemon juice (because really our punch is lemonade). You can also do this color change trick on purple cauliflower. Steam some purple cauliflower and then squeeze a bit of lemon juice on it, and voila! You’ll have a cool pattern of pinks and purples on your side dish for dinner that night. What is actually being affected when you introduce an acid to a purple plant is something called the pH level. A quick Google search informs me that pH is an abbreviation for “potential hydrogen” and that a pH level is the measure of a solution’s hydrogen-ion concentration. Well I’m no scientist, and that was a lot of scientist lingo up there. I don’t quite understand it all. I really should take that food science class I’ve been eyeing. Then you all would have to call me Miss Scientist Chef Daisy. Has a nice ring to it, huh?
Anyway, I may not understand all the science behind this magic party trick, but I do understand that it is a super cool and fun show for kids of all ages at birthday parties. Or just at home on a weekend when you’re in the mood for a little food fun. And really, who isn’t in the mood for some food fun? Also, it is so easy to do!
Magical Punch Recipe
1 head purple cabbage, roughly chopped
2 cups water
1 pitcher of your favorite lemonade recipe
1. Place the chopped cabbage in a strainer over a large, shatter-proof container.
2. Bring the water to a boil, then pour over the cabbage. The resulting liquid will be bright blue.
3. Pour the blue liquid into a clear pitcher or several small drinking glasses.
4. Pour the lemonade on top of the blue water and watch at it magically (science-ly) turns bright pink!
Notes: Purple cabbage turns water blue the second they touch. So you can skip the boiling water part, but the resulting liquid will be very pale blue. The boiling water helps create a darker, brighter blue. If you want to turn the water an even darker blue, or a purple (which will make the resulting pink darker), you can add the cabbage to the boiling water, turn off the heat, and let it soak for 10-20 minutes. The only downfall to the soaking method is that the water will start to take on the flavor of boiled cabbage (not very tasty). However! You can combat this by just adding tons of sugar or honey to the water before boiling to make a simple syrup.