For this week’s Coffee Basic’s post, we’re exploring the timeline of freshness in coffee. Whether you’re new to specialty coffee or have been on board for a while, it is very likely that you know coffee freshness has an impact on taste. To be sure, freshness is a hallmark of specialty coffee and is one of the main factors drawing many people to explore what the industry has to offer. But what exactly do people mean when they say freshness is important? And what does it mean to say that a coffee is “fresh”? How does freshness impact the coffee you drink at your local coffee shop or at home?
Freshness starts where coffee is grown.
How do you measure freshness in unroasted or green coffee?
The way a coffee is picked, processed, dried, stored, and shipped has a huge impact on the longevity of the green coffee based, measured by the degradation of the flavor of a coffee over time. For instance, our coffee department is finding that one of the most crucial aspects of green coffee stability over time is that it be dried to a moisture content between 9.5–10.5%. This and other factors help the unroasted coffee remain stable and free from the negative effects that too much moisture can cause, such as mold or physical degradation. Ideally, it is best to roast coffee as soon as possible after it arrives from origin. In most cases that means the coffee will be used within four months of arrival.
How do you measure freshness after coffee is roasted?
Moving from unroasted to roasted coffee, there are two main factors to consider when thinking about freshness: When the coffee was roasted and how it is stored once the bag is opened. Just as you would want to use fresh produce soon after it’s picked or fresh bread soon after it’s baked, coffee is best soon after it’s roasted. To learn more about the roasting process, go here.
The best-case scenario is that coffee is used within two-to-four weeks from roasting for peak flavor.
Another factor to consider is how long coffee should “rest” once roasted before grinding and brewing.
So, how long should coffee rest before grinding and brewing?
One of the hallmarks of specialty coffee at its inception was the idea that coffee should be used as soon after roasting as possible. The general convention has been that you should start using a coffee 3–5 days off roast for brewed coffee and 5–7 days for espresso. While these are still good guidelines, as the specialty coffee industry has shifted toward purchasing more-dense green coffee grown at higher-elevations and lighter roast profiles, the optimal window to start using roasted coffee is wider than before.
Why do you need to let coffee rest?
The purpose of letting coffee rest is to allow carbon dioxide gas to escape. This enables more-efficient, even brewing, resulting in more-balanced and sweet coffee. With more-dense, lightly-roasted coffees, the best flavors can appear in the range of 10–14 days after roasting. A prime example of this from our coffees would be Idido or other East African offerings. These coffees really start to open up in that range of 10–14 days off roast with an amazing balance of floral aroma and sweetness. Consider this longer ideal roast window when you purchase coffee at your favorite coffee shop. That bag roasted a week ago may actually just be coming into its literal and metaphorical sweet spot. Be sure to look for a “Roasted On” date rather than a “Best By” date. In short, our coffees are tasting great throughout a wider window of time than ever before.
Once you’ve purchased coffee, how should you keep it fresh at home?
While there are a number of opinions on how to store coffee, our best recommendation is to store whole bean coffee either in the original packaging—sealed tightly with the excess air forced out of the bag via the one-way valve—or in an airtight container that allows carbon dioxide to escape without letting oxygen in. In either case, coffee should be stored in a cool, dry space and away from direct sunlight. Once opened, it’s best to use the coffee within a two-week period for best results.
Avoid storing opened coffee in the fridge or freezer. Coffee is very porous and easily absorbs moisture, along with any odors that may be hanging around.
As always, if you have questions regarding this topic or other coffee-related thoughts, please reach out using the help button in the lower right-hand portion of this page!