People in specialty coffee can become obsessed with freshness, and with good reason. Beans that were roasted months ago degrade and lose flavor over time, so it’s good to use coffee that has been roasted recently. That said, your coffee can actually be too fresh, and your brew can suffer as a result. 

Coffee beans have large amounts of volatile gasses trapped within them. The coffee roasting process transforms carbohydrates and amino acids into carbon dioxide as beans are heated. That means that when coffee is very freshly roasted it has so many gasses trapped within it trying to brew the coffee will lead to gas discharge blocking water absorption, and your coffee being under-extracted.

Simply put, it’s like riders getting off the subway train as the same time riders are trying to enter—inflow and outflow cannot happen simultaneously. As a result, super-fresh coffee that is actively discharging gas might taste flat, or sour, or a little bit salty. That carbon dioxide gas trapped within coffee beans also converts to carbonic acid when it encounters water. That acid is astringent and sour, which is another reason overly-fresh coffee can make you pucker.

Coffee peaks in flavor four to fourteen days after it’s roasted. Dark roasts are more porous, so they’re ready to use a little faster than denser light roast beans are. Use that dark roast on day three and you’ll likely be fine, while you might want to wait until day five for a very light roast. That will give the beans time to properly degas and offer up their range of flavor to your water when you brew them.

For espresso, due to the very short extraction time and high pressure, you’ll want to wait even longer to use your beans—we recommend seven to ten days before you load your portafilter.

Freshness in coffee is important, and at Dawson Taylor we pride ourselves on getting coffee into your hands when it’s barely out of the cooling tray. However, with improvements in coffee packaging, it is okay to keep your coffee longer than you might now. In sealed, airtight bags with a carbon dioxide release valve like we sell our coffee in, coffee has no noticeable decrease in flavor for as much as 90 days. Once coffee is exposed to air it degrades faster, but coffee kept in a cool, dark, dry environment for up to two months should not taste much different than coffee that is only two weeks old.

Decaffeinated coffee does degrade more quickly than conventional coffee, as removal of caffeine breaks down the cellular structure of the green coffee, so you will want to use your decaf coffee more quickly than your caffeinated beans.

Keep it fresh—but not too fresh!