Play-dough, some simple kitchen chemistry you can play with a toddler to keep them busy for at least 20 minutes- well, for Harvey anyway.  He was more interested in putting a cap on the water bottle but eventually got into the mess.  I wanted to use frosting/icing instead of the flour as Harvey stills love putting things in his mouth, but Jaz asked why would I be encouraging him to eat the dough!  So point taken – I decided to go for a salty dough with the hope that it would put Harvey off.  But would you believe?? Harvey didn’t even try to taste the dough!!!

Ingredients

• 3 x cups Flour
• 1 x cup Salt
• 1 x cup of Water
• Food colouring
• Oil ( ~ 1-2TBS)
• Large mixing bowl
• Large spoon for stirring
• Cookies cutter for some fun

Method/Chemistry

1. In a large mixing bowl, add all the dry ingredients and stir to mix.  This mixture has no chemical reaction taking place. Theoretically the two substances could actually be separated using a very fine sieve

2. Add a few drops of food colouring to the water and mix them together (note we chose the green colour).  The resulting solution becomes green.

3. Add oil to the green solution.  Oil is immiscible in water and floats on top as it is less dense then water

4. Add the solution to the mixture and stir to combine.  Once the all the solution has been absorbed, it is fun time! Use your hands to knead the mixture until it starts to turn into a ‘dough’.  Take the dough out and continue to knead until the play dough is formed.

Flour are composed from starch and protein and therefore by adding water to flour, it allows the protein to develop into a thick, cohesive, elastic mass.  The purpose of salt is to assist the proteins to stick together more strongly and also as a preventative to stop the dough going bad).  The oil coats all the ingredients and preventing the dough from drying out.  Lastly, the molecules from the food dye gives the dough its colour.