C&D Tins are not vacuum packed! C&D believes that proper aging requires some air in the tin. Now, as for storing aromatic blends, don't do it for long term. It does depend on the several elements. One is the tobacco elements of the blend. Another is the "sauce" element of the blend. And, finally, the method of storage. Your best bet is to store it in the tin unopened. Personally, I have had great results with my Captain Bob's Blend being stored in the original tin unopened for up to three years. However, I will always fall on the side of this fact - Aromatic blends are intended to be smoked when manufactured. I suggest that you follow that advice for the very best results. There are many factors (as mentioned) that affect the storage process. You might ask why do I feel CBB is fine after three years? Well, it is because the one-pound tin is tightly packed under pressure, with no airspace. I have not noticed any change after three years. Simply put, the same cannot be said about the packaging of other aromatics. Then, there is the sauce itself. Some sauces break down in intensity and actually do change chemical character with time evolution. I know this to be a fact! So, you will have to experiment with aromatics. I would just not recommend buying and storing your favorite aromatic for an extended period of time (years) without consulting either the manufacturer or someone who has actually stored it that long and formed a judgement. Please remember that all tobacco's have flavored casing and/or topping. What determines an aromatic versus a non-aromatic is simply a matter of "DEGREE"! Therefore, my conclusion is to not indefinately store heavy aromatics and expect them to be as good as when purchased. My opinion is that it is more than a fair bet that those aromatics will, indeed, deteriorate.
Perhaps long term storage is where the drug store blend may shine. The chemicals and poly g that we sometimes complain about may make them the perfect aros for multi year storage.
This is an interesting question as there are so many threads about stockpiling. It would be sad to have stockpiled many pounds of aros only to have them fail when opened 10 years from now.
I recently opened a tin of Peterson Special Reserve 2004 that I picked up in a three year old B&M. No doubt an aromatic, and I distinctly detected a raisin scent in the tobacco. It had a mild bite to it when opened, which went away after about 3 days. I can taste hops while smoking it.
Since I do not know how it would be when fresh, I have no way of telling whether it improved or not, but I like the way it tastes and smokes, so I dont think it was a bad deal. I should point out that this was packaged inside a sealed foil pouch, then placed in an unsealed tin with hinged top.
My 2 cents! I have aros stored in Ball mason jars for over a year and there has been NO change. That's the simple answer. There's a lot of theories and I think the best thing to do is just do it and learn from experience.
At the rate I smoke (slow) and with the number of tins I have open (many), I guess I'm an experiment in progress. What I noticed was that in their original packaging (tins, bags, pouches) my blends were slowly drying out after opening. So I now have 250 ml mason jars that I immediately transfer the tobacco to after unsealing the tin. It slows down the process, but some moisture is lost every time I open the jar.
Other than the drying, I can't say I've noticed changes in the aromatics (or the englishes, either). My oldest open stock is about two years old (since opening).