Stevia seems to come in a number of forms: white powder, green powder and liquid. Were there any instructions or information with your Stevia?

The problem is that Stevia is not "legal" (in Canada at least) as a sweetener and can only be sold as a "supplement".

I think that the white powder which you mix in water makes the best sweetener (and the least expensive). Or the liquid. Some forms can have a licorice or herbal taste which is not to everyone's taste.

How about going back to where you bought it and ask some questions about how to use it?