Wizard's Brew is number three on the list provided in the above link. I also love that blog and follow it for great ideas.
Yesterday, both girls and my niece and nephew made Wizard's Brew. They LOVED it. The experiment was simple to follow and gave a great "wow factor." The mess was minimal. We all enjoyed it and will definitely do it again. SO FUN. The kids wanted to keep the brew going, but it was time for dinner and our supply of vinegar was running out.