Cortezattic Said: Maybe python can chime in on this with some of his experience in "canning."
Here are my opinions on jarring/storing/aging tobacco:
Almost all tobacco will arrive to you, whether purchased in a B&M or online, with the proper amount of moisture and even sometimes a little too moist. I would just jar it up as soon as I got it and put it away in storage. If you are using airtight jars (mason jars are airtight), there is zero chance of losing moisture, but at the same time it will not release any moisture either.
You may need a slight amount of moisture to help it to age, but a very slight amount. I would never add more moisture before jarring it up unless it was completely dry to the point of crumbling. Like I said earlier, the moisture content upon receiving the tobacco is plenty enough to jar it up, with a few exceptions. I would rather store it a little on the dry side than add moisture and risk ruining and losing a large amount of tobacco from mold. I have never had to add any moisture to any tobacco before storage.
When in doubt about adding moisture before jarring, IMO, jar it up on the side of caution and don't add any moisture to it.
By not adding moisture, the worse case scenario is; the aging process MIGHT be hindered and slow it down a bit. But the tobacco will still be smokable even if you have to re-humidify it when you open it so you can smoke it.
If you add moisture before jarring it up, the worst case scenario is; the tobacco will mold during aging and you will lose it all. Keep in mind that you can always re-hydrate it if you have to, but you can not remove mold.
In all my years of storing tobacco, I have never had any problems with mold.
This pretty much refers to bulk tobacco because tins can be stored as is. But if you open a tin and don't plan on smoking it all within a few weeks, put it in a jar to keep it from drying out.
