eli5: why does the second shampoo make more foam ?

Question

eli5: why does the second shampoo make more foam ?

In: 0

Answer 1

Because there’s less oil/dirt in your hair.

You can try an experiment to show how it works: Take a pan and put some oil in it, then wash it with dish soap. There won’t be as much foam, but it breaks down the oil. Once the oil and soap are rinsed off, add dish soap again and it will foam a lot more.