Storing opened tins

[OleFattGuy]

Hi all,
as a relative newbie to both the forum and pipesmoking (have been lurking the forum for some months and smoking the pipe for about a year now) I have a question.
A friend of mine went to Copenhagen (I live in Sweden so it´s not all that far) and I caught the opportunity to have him buy me a couple of hard-to-get tins of tobacco. I now sit with a nice heap (check it out on my pipeblog http://olefattguy.blogspot.com ) of un-opened tins, namely;
MacBarens Dark Twist 100 g
McConnells Pure Latakia 50 g
Dunhills Early Morning Pipe 50 g
Peterson University flake 50 g

Quite a variety of tobacco´s and I am eager to try them all (well maybe not the Pure Latakia, but it might mix nicely with the others, was my idea).
However I don't wanna open them all to find out that a week or so later they are all dried out and unsmokeable?
At the same time I find people writing about smoking tobacco from tins they opened last year??
What's the deal here? Can I keep tobacco for years on end even though I broke the vacuum seals? All kinds? Only flakes? How about Dark Twist(roll cake)?

[OleFattGuy]

Can't wait
I'll start off on the ... ummm, let me see ... 100g DarkTwist ... OR ... 50g EMP ... I've tried the UF, I know it already so I'll save that one... Pure Latakia ... nah don´t think so.

Jeez this is hard, but ... Ill go for the EMP!
Check out what it was like on my blog...( http://olefattguy.blogspot.com ) and check out some of my pipes while you're at it!
The DogTurd or Li'lAbnersMom for example...!

[KurtHuhn]

I normally dump opened tins of tobacco in a Mason jar (aka: canning jar) so that the tobacco stays fresh. Unless, that is, I know I'm going to smoke the whole thing in about a week.

[Nick]

Mason Jars are the way to go.

[OleFattGuy]

Aha.
OK. I'll have to check those jars out, see if they are available in Sweden.

A ziplock bag around the tin (has to be big enough to house the tin) should help things a bit though? Or just plain freezer plastic bag tied around? As a budget alternative I mean.
Maybe I could use Grandma's old trick and suck all the air out before tying the knot on the bag :think:

Thank you guys for the tip!