Mmmmmm....cake; sweet, fluffy and delicious. But what, exactly, turns a dense, wet mess of batter into a light, airy cake?

Here's a hint: It's not yeast, which you'll know if you've made a cake from scratch. Bread: yeast, beer: yeast, even some kinds of doughnuts: yeast. Cake?

 

 

 

 

If you want to know the one ingredient you must never, ever leave out of a cake, check out this video -- and try not to get too hungry.

 

Did you know the answer?

 

If you like this video and want to see more like it, make sure to subscribe to CafeMom Studios YouTube channel.

 

Image via Debs/Flickr