"수프에 후추가 있어요."
Translation:There is pepper in the soup.
후추 is ground pepper, wheras 고추 is pepper the vegetable (and also slang for penis)
I was wondering the same thing - I answered an earlier question like this and got it right. Not sure if that means it actually is right, though...
I was wondering about that too... also if both are okay then how would you say "there is soup in the pepper"? haha