Another food colouring post! (Hey, I have so many bottles, gotta find some way to use them up….)
Porthos asked to make volcanoes the other day. We didn’t have sodium bicarbonate on hand, so on the spur of the moment, I suggested something different. We know that every time we use food colouring with water or vinegar, the solution completely changes colour. I asked Porthos what would happen with oil and he assumed the same thing would happen.
“Let’s see” I said.
So we poured some oil onto a dish
Then we put in a few drops of food colouring
And even when we agitated the mixture with a chopstick, and added some more colouring, the stuff just wouldn’t mix. Instead. we had some really funky oily art going.
If you want to get into the science, the essential point is that food colouring is water-soluble, but does not dissolve in oil.