Pipe Novelist,
When you say you leave the tins "open for months", do you mean that literally? No lid, just an open tin sitting out for months?! That IS "crispy" indeed.
I'm just curious, what brands to you "age" like this for months? I assume heavily preserved blends (those with lots of PG, like drugstore brands) take longer to dry out than unadulterated leaf.
Like I said, I'm just curious.