JK Rowling just had her live chat with fans on Bloomsbury’s site. I only got to see the end because I slept in. So I got the beginning of the transcript I will post from Leaky.

Jess Mac: What was the third smell that hermione smelt in the amortentia potion in hbp (ie the particular essence of ron)

J.K. Rowling: I think it was his hair. Every individual has very distinctive-smelling hair, don’t you find?

DO NOT CLICK READ MORE IF YOU DONT WANT TO SEE THE CHAT!