Video Demo: Watermelon Caviar

I recently started a food science club at school with a fellow teacher.  It's a good way for me to try out new stuff with a small group of students, that I eventually want to incorporate into my classes.  It's like a real life R and D department.  I recently posted about a polymer called sodium alginate. I got a response from Earl Lee on how to make watermelon caviar. So I decided, let's try it out with an after school club.  It demonstrates a technique used in molecular gastronomy. A polymer (which is in one of our standards), sodium alginate, is mixed in with watermelon juice. The mixture is then carefully inserted, with a syringe, into a solution of calcium chloride. A chemical reaction happens between the calcium chloride and sodium alginate to form calcium alginate. The calcium alginate is not soluble in water and thus forms a gel around the outside of the watermelon juice. The calcium alginate watermelon spheres are edible. We then experimented with making spheres of cola using the same technique.  The students loved the more intense (not to mention the more sweet flavor which their palettes are more geared to) flavor of the cola.

Video Demo: Flour Fireball



This is another favorite demo of mine.  Throughout the years I had mixed results.  I finally figured out that Gold Medal all purpose flour works the best with some preparation.  I sift a small bag of flour to reduce clumping and ensure the separation of particles.  When doing this demo be aware of what kind of fire alarms/detectors are used in the building. In my classroom there is no sensor that will go off.  Where I recorded the video, our school's multipurpose room, it (it was about 30 feet above the demo area) could detect the heat/smoke that was released (the alarm sounded about 1 minute after the actual demo).