How to Properly Store Coffee
When was this roasted? How long is it good for? Should I keep it in the freezer? All common questions, and I’ll answer them here, as I discuss how to store your coffee, and how it changes over time.
When green coffee beans are roasted, moisture inside the beans is released at various intervals (much like popcorn, only not so violent). Cracks form on the outside of the beans, allowing that moisture to escape. These cracks also allow carbon dioxide to escape, which is generated inside the roasted beans because of the browning (Maillard reaction) and other chemical changes. Because CO2 can affect both flavor and aroma (negatively), a “degassing” period is needed after roasting and cooling.
Much of the CO2 escapes in a short period, around 24 hours after roasting. But for some coffee, especially the lighter roasts, it may take longer, for up to several weeks, since the beans are more intact. I prefer to let most light roasts I’ve done age for 5 days or so. It’s a myth that the fresher (i.e. sooner to the roast date on our packaging) the better.
So, you might think, why not just dump the beans in an open container for a week before using them? Well, there’s a tradeoff. We don’t want the CO2, but we also don’t want oxygen, which degrades the natural oils in coffee beans and quickly reduces the shelf life. Hence, we fill our biodegradable-plastic-lined bags shortly after roasting, so they’re in an airtight package.
But if the coffee is still actively releasing CO2, wouldn’t the sealed coffee bag blow up? It could, though our bags include a 1-way biodegradable valve that allows CO2 to escape, and no oxygen to enter. On the shelf, your unopened bag will be just fine for 4-6 months. After unsealing the bag, it’s a different story.
Those beans will begin to degrade immediately, and should be used within a week and a half. You can prolong their life by storing in a dry, dark place, and only grind a small amount at a time. Ideally, grind only what you’re going to use immediately. I like this method, and grind my beans fresh for each cup, but my wife instead grinds a larger amount every few days. I like to keep our whole beans in a container on the counter, so a medium size Fellow Atmos works well for us.
It even has a vacuum feature, so after closing it, you can remove most of the oxygen. Doesn’t seem worth it to me for daily use, but in hot humid weather (which can carry a lot of moisture) it would help.
What about your freezer or fridge? Well, that’s a pretty dark and cool environment, which is good. It could be moist, so you’d need a tightly sealed container. When ready to use, remove the required beans as quickly as possible so moisture doesn’t form on the surface of the unused beans (like on the surface of a cold glass on a hot day). A little moisture on the surface of your daily beans won’t hurt, and will also reduce static electricity when grinding.
So you have storage options. We tend to drink our coffee pretty quickly, so it doesn’t have a chance to go stale. My recommendation would be to buy the amount you’d drink in a couple weeks, and don’t worry too much about advanced storage techniques – cool, dark, and covered is fine.