Champagne- black current - water. The magic glass.
This is definitely a show stopper and for the teachers who like to perform in class this reaction is a must.  

Materials.
Hydrogen peroxide 30% solution. 29mL
Potassium iodate 4.3 g
Sulfuric acid 1 M, 10 mL
Soluble starch 0.1 g
Malonic acid 1.5 g
Manganese(II) sulfate (MnSO4.H2O) 0.4 g
Distilled water 300mL
4 X Beaker 250 mL
3 X 50 mL Measuring cylinders
Stirring rod.
1 X 200 mL Beaker

  
 Using the material above three separate solution will need to be prepared.

Preparation of the three solutions
Step 1 Prepare an 8.6% hydrogen peroxide solution by adding 30 mL of the 30% hydrogen peroxide solution to 250 mL beaker and adding70 mL of distilled water.

Step 2 Prepare a 0.2 M acidified potassium iodate solution by adding 10mL of the 1.0 M sulfuric acid solution to another 250 mL beaker and add 90 mL of distilled water along with 4.3 g of the potassium iodate and stir to dissolve the potassium iodate.

Step 3 Place 100mL of distilled water into a 250 mL beaker and bring to boil. Add the 0.1g of soluble starch and stir until completely dissolved. Allow the solution to cool before adding the 1.5 g of malonic acid and the 0.4 g of manganese sulfate. Stir until all the solutes are completely dissolved.

Procedure

Step 1 Prepare the following.
- use a 50 mL measuring cylinder to transfer 40mL of solution 1 into the first 50 mL beaker
- use another 50 mL measuring cylinder to transfer 40mL of solution 2 into the second 50 mL beaker
- use another 50 mL measuring cylinder to transfer 40mL of solution 3 into the third 50 mL beaker

Step 2 Using a 200 mL tip the 40 ml of solution 1 and 2 into the beaker. Finally add the 40 mL of the solution 3 to the 200 mL beaker and stir the solutions.

The resulting solution should oscillate between orange, black and clear for up to 10 minutes. An experienced teacher should be able to predict very accurately the colour change and hence command the solution to change from black to clear water. Bubbles of gas add a sense of realism to the champagne colour.