I know this has been talked about but I have a problem. I am using a 2 liter bottle with a 1 liter as a drop/don't let the gunk get into the tank bottle. I mixed 2 cups sugar 1/2 teaspoon yeast and luke warm water up to just before the curve of the bottle. That was a day and a half ago. I have a good seal but no CO2. Anyone have any suggestions? This dosen't seem like rocket science but I missed something somewhere. I am using yeast fron the baking area in my local grocery store.