No matter the coal this issue can be resolved. Like everyone else said make sure your coals are completely red no black on the coal whatsoever. Start them on the outside of the bowl. Make sure your hookah is throughouly cleaned before the session. If you have the original hose that came with your hookah it is possible that the taste got stuck in your hose. I found that hoses with the metal coil on the inside hold onto the tastes more than washables. That being said blow through your hose for a while and see if you can knock out that taste
I hope I helped.