A reader asked via email:
How do you store your coffee?
I get this question a lot.
Good coffee storage needs to be airtight in one direction — for the first day or two after roasting, the beans emit small amounts of carbon dioxide, so air should be able to escape whatever the beans are in. But to prevent early staleness, outside air shouldn’t be able to enter.
My solution is quite simple: since I roast my own, I just use zip-top valve bags from Sweet Maria’s, the same place I get unroasted beans.
If valve bags aren’t your thing, I also like the Airscape jars. I suggest getting the tall “64 ounce” size, though — the short “32 ounce” jar won’t hold a full pound of beans.1
Proper storage will prevent the beans from going stale early, but they’ll still lose most of their flavor and settle into a dull, flat flavor profile by about two weeks after roasting. Refrigerating or freezing the beans doesn’t seem to extend this timeline and can introduce moisture in practice, so don’t do it — just put them in something airtight and leave them somewhere dark and dry, like a kitchen cabinet.
Because of that two-week flavor timeline, most storage tips only matter if you’re getting freshly roasted beans from home-roasting, a local roaster, or a fresh mail-order service such as Tonx.
If you’re buying beans from Starbucks or most grocery stores — yes, even Trader Joe’s (especially Trader Joe’s)2 — they’ve probably been roasted more than two weeks ago, so the flavor has already become dull, and it doesn’t really matter what you put them in. Use whatever’s convenient.
Airscape’s sizes are misleading: my “32 ounce” jar does indeed fit about 32 ounces of water, but only with the lids off. If you actually want to attach both lids to make the proper seal, the usable volume drops to about 20 ounces. Still, I like the Airscape — the short one just holds less than I expected. ↩
The easiest way to cheat the two-week flavor deterioration is to roast extremely dark. The burnt-ash flavor lasts much longer than the flavors you get with more reasonable roasts… but it tastes like burnt ash. Customers think dark roasts are the only way to achieve “strong” flavor because they’ve usually never had fresh roasts, so they think all coffee is “bitter” and “burnt”, but it’s actually just a cheap trick to extend the shelf-life of perceived flavor and strength.
Starbucks leans on this trick a bit, but nobody does it like Trader Joe’s and their extremely dark roasts that retain their strong burnt-ash taste for many months. ↩