How fresh is your coffee? When was it roasted? If you roasted it yourself, you almost certainly know. [If you don’t roast your coffee and think you might like to, be sure to see our coffee roasting series.] If you purchased your whole bean coffee from a specialty coffee shop, you’ll probably have to ask them when it was roasted. If you ask them, and they don’t know? It may be time to find a different coffee shop. [And if you don’t know when your coffee was roasted because you bought it pre-ground in a can, then you may be one of those other people that we’ve been talking about….]
Roasted coffee beans are generally best used within 3 to 7 days of roasting. You can extend the shelf life of your roasted coffee by a week, or maybe even two, by sealing it tightly in a bag with a one-way valve [which allows CO2 from the coffee to exit, but doesn’t allow air to enter]. If you’ve bought more roasted whole bean coffee than you can use in a week or two, you can keep unopened valve-bags in the freezer for up to a month before it loses a significant amount of flavor. As a general rule, buy only as much as you’ll use soon. Or roast your own.
While roasted whole-bean coffee can be stored for a time, ground coffee loses its essential oils and flavors and goes stale within an hour or two. To make a great cup of coffee, you really need to grind your own. That leads us to….
Your brew method will determine how fine, or how coarse, your coffee should be ground. Drip brewing requires a fairly fine grind… it doesn’t allow for a lot of interaction between water and coffee, so it’s important to maximize the flavor extraction with a grind that’s roughly equivalent to coarse sand.
At the other end of the grind scale, a French press [or cafetiere] requires a fairly coarse grind, otherwise you’ll find it difficult to press the piston through the pot, and you’ll end up with coffee that’s both over extracted, and muddy, too. The trade-off, of course, is that unlike drip-brewing, brewing with a press pot offers you complete control over how long the coffee should brew.