February 16, 2005
I was in Dunn Bros. (the Grand Ave. store) last night buying some beans. As the barista was ringing me up, a guy in line asked how long my coffee would be good. "About a month," the barista replied. I must have looked stunned, because she eyed me curiously: "I take it you disagree."
Do I ever. There is a marked decline in coffee's flavor over the course of a week after roasting. If memory serves me correctly, something like 70% of the compounds responsible for coffee's flavor are gone in that time, transformed into something far less pleasant. The difference between a week and a month is obvious. Try it yourself. Granted, I'm a connoisseur snob about these things, but I don't ever keep coffee more than two weeks, and by that time I've stopped drinking it because I can't stand to — and because I forgot it was in the cupboard. Call me crazy, but I like my coffee to actually taste good.
At this point, she countered, "but my grandparents keep coffee for a month and they like it!" Good for them, glad they're happy. You'll note that they don't work for one of the premier coffee roasters in the Midwest and that it's not their job to know things like this.
Here's my rule of thumb: buy only what you can drink in a week or so from a local roaster. I realize that in many corners of the world this isn't possible, but if you can, do. (If you can't, consider home roasting.) Store the whole beans in an airtight container at room temperature. Use them as soon as you can.
Enjoy.
When I was working at the Roastery, we had a report tucked away behind the counter, someone's master's thesis studying the chemical process of how coffee goes stale. They used beans that we roasted, which is why we had the thesis. I wonder if I could dig that up…
