IT Helps ... Air is the enemy to any food storage. Although some here advise to keep a little breathing room in the jar others don't. I open mine to often, fetching more, to care about aging. From reading here there is aging and storage. If aging you are not accessing the tobacco for some time. Every time you open the lid you are stopping the aging process. When jarring for storage you are just keeping it fresh while you smoke it. Either way you want to keep the air down, and glass is the best.
Baggies and opened tins let air in and out they say. I have some bulks though in a good sealed baggie that have sat for a month without drying out yet, and a favorite arro that has been in a pre-opened tin since thanksgiving and it is still great. HOWEVER that won't last for long, but then again neither will the tobacco cause I'm gonna smoke it.
I jar for mostly storage, except for the tobaccos I bought and don't really like. They get aged as a side effect to the lack of interest. Even my most favorite tobacco that is expensive gets accessed at least once a week as a treat. That's the one in the pre-opened tin. It is a quality tin and has a rubber seal on the lid. Otherwise it would be in a jar as well, and if I had the space I would jar it all.
Hope that helps and is not info overload. :
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