I haven't had the funny after taste issues, but can see how that could happen. For my Pipe tobacco I use a deer skin lined silk pouch. I think I got it from Speedy and Kara (Corner Clothiers) years ago when they first started.IT is not air tight, and will allow moisture to escape, but it is pipe tobacco and shouldn't be super moist anyway. I also keep this bag full of pipe tobacco in my humidor when I am not carrying it, so it may have some residual humidity/moisture in the material.
Mitchell L Critel