Yup, the reason you do it is to remove the bad taste and smell from the alcohol. Are you trying to filter a receipe or just a sugar wash? If you are using a receipe then you will remove all the taste that you have made, you will taste nothing but pure alcohol. As far as removing the alcohol, I don't think that the filter will do that. If all you had left was water then that is what you started with. Put a drop of it on the floor and drop a match to it. Does it burn blue? At all? This is my tell tail sign of the quality of the alcohol, the color of the flame. My stuff is from blue to invisible, that being the meth, burning off I think, but then again I only do a sugar wash and there is no possibility of methenol produced there because you have to have a product with pectin in it to get methenol. Did you clean your carbon after the filtering? Did it smell bad when you boiled it? These are tell tail signs of what was removed. Bad smell, fusal oils and yuck....no smell, nothing...this is all only my opinion from doing it for a while, but I don't think your carbon removed any alcohol.....jimbull