But maybe not when the kids need to be entertained during the summer vacation. So maybe you can perform some chemical tricks.
put a teaspoon of red wine in a glass and add some water until it looks pink. (If you think this is alcohol abuse, you can use a crushed blue berry.) Sprinkle in a few grains of baking soda (Arm & Hammer, obtainable at the Turkish supermarket) until the wine turns blue. Add a few drops of lemon juice to see it turn red again. Next bore the little ones to tears when you explain about acid-base reactions.
In case you want more inspiration: go to Zin in de zomer