kasey wrote:... may have absorbed too much moisture and transferred some paper bag odor to the tea.
I think this goes with a general rule of thumbs for smells. If the smell is strong, it will get leached into the tea. Different papers have different sizings, pulps, materials, and smells. Just smell the paper. If it has a noticeable odor, it will likely be leeched by your tea. If you can not smell it, then any odor the tea leeches will also likely be undetectable.
Also, if you want to go further, but some porcelain or ceramic containers, put the maocha in, and put cheesecloth over the top to keep out stray junk/insects/ghosts. Store where you keep your other tea. (Consider humidity, odors, sunlight, etc)