Welcome to the Get My Grades Lab! This new blog series will carry out a series of popular GCSE Science experiments over the coming weeks in order to make sure you know exactly what is coming up in your exams and how all of the experiments are carried out. In our first video, we show you how to carry out an iodine test for starch on food samples.

This is a classic GCSE Science experiment. If the food sample turns blue/black when iodine solution is added, it indicates that starch is present. If there is no starch in the sample, the iodine solution will remain orange/brown. We carry out the experiment with 7 different samples:

  1. Soluble Starch
  2. Potato
  3. Ham
  4. Onion
  5. Pasta
  6. Apple
  7. Bread

Soluble starch was used to demonstrate the positive result and confirm the liquid was indeed iodine solution.

Starch was identified in the potato, pasta and bread. There was no appreciable amount of starch in any of the other samples.