As mentioned above , turmeric works as a indicator and turmeric gives no color when it is mixes with the acid .
So , suppose we have only turmeric and we have to find out that whether the substance in acid or neutral . So , How we can find it ?
Turmeric changes its color only in basic medium. It turns to reddish brown in basic medium while in acidic medium there is no change in color.
for eg : when a drop of soap solution is dropped on turmeric stain on cloth it turns to reddish brown stain indicating basic nature of soap .