We talk about density as we demonstrate the difference in the regular vs dried cranberries vs popcorn kernels floating in plain water.
Fresh cranberries will float due to air pockets in them, but the dried ones sink as the air pockets are no longer there. Popcorn will also sink.
The carbon dioxide bubbles cling to the rough surface of the dried cranberries/kernels until they are able to float to the surface of the liquid where the bubbles pop, causing them to sink. This will continue, giving that "dancing" look for several minutes. I also plan to discuss why the cranberries "dance" longer than the popcorn and why it is much smoother. This is all about mass and texture! Dried cranberries are lighter and rougher so it's easier for the bubbles to cling to them and they require less gas to rise. The popcorn kernels are heavier and smoother so they need more gas to rise, but they are harder for the bubbles to cling too!
