While many things make specialty coffee preferred to the stuff traditionally sold in supermarkets, concepts like green sourcing and roasting philosophy can be slightly difficult to explain. The concept of freshness, on the other hand, is pretty easy to understand, especially for a coffee lover. Like all things food — generally speaking — the fresher, the better.
For that reason, freshness of a coffee bag quickly became the main selling point for a new generation of coffee roasters. Once a coffee drinker has experienced the difference between stale supermarket coffee and freshly roasted beans, it's easy to understand why. So, how long do coffee beans last?
How long will coffee beans stay fresh after roasting?
When coffee beans are unroasted (AKA green coffee beans), they will stay fresh for quite an extended period, even up to 12 months. But once the coffee is roasted, oxidation starts to occur faster, which can ultimately impact the coffee taste.
You can compare it to bread; flour stays fresh for a year, but once it's been turned into bread and baked, it deteriorates rapidly. However, when it comes to the coffee bean, there are multiple factors involved that can increase or decrease the best-by date. This can include the aroma, coffee bag used, coffee flavor and brewing method.
The state of the green beans pre-roasting will also have an impact on the shelf life. For example, storing the green coffee in air-tight Grainpro bags compared to leaving them in jute bags will significantly extend the best-by date.
Coffee is an agricultural product that is a lot less uniform than people realize, especially considering the various coffee processing methods. The density of high-altitude Central American washed beans, and that of a wet-hulled Sumatran coffee will be very different. Some Indonesian roasters will even argue that wet-hulled green coffee beans can only be stored unroasted for three months before degrading.
Conversely, some coffee experts argue that letting naturally-processed coffees rest for a longer period of time is beneficial.
Coffee that is roasted very dark loses freshness more rapidly. You know that shiny surface on espresso beans? That's oil. When it migrates to the outside of the bean, it will be exposed to air and can go rancid.
For that reason, lighter roasts will have a longer shelf life, since the oils stay inside of the fresh coffee beans.
So, “How to store coffee beans properly?” and “What is the best type of coffee storage” are the next questions at hand. The type of packaging used will have a significant impact on coffee freshness and flavor, as well. For example, if a coffee is stored in a dark-brown paper bag, it could rapidly lose its freshness. However, when using a nitrogen-flushed bag with a one-way valve, the freshness is extended considerably. Oxidation will usually not accelerate until you open the bag of coffee and allow air in.
All combined, dense, high-altitude beans that have been stored well and packed in one-way valve bags are your best bet — these roasts are usually dropped well before the second crack, which again prolongs freshness.
When it comes to a fresh coffee like that, it's fair to say that it will taste delicious anywhere from five days to six weeks after roasting the whole bean coffee. (Though, it's more important to consume ground coffee beans rapidly after opening the bag).
On the other hand, the "window of deliciousness" is typically a bit more narrow when it comes to espresso beans. Brewing espresso beans that are a little bit too fresh can cause vast amounts of crema to be produced. Old ground coffee beans, on the other hand, tend to create a flat flavor with only little crema. And again, dark-roasted, oily espresso beans tend to go rancid more quickly.
To avoid this, only leave a few days worth of good coffee in the hopper, where oxygen can wreak havoc, or consider single dosing if your coffee grinder allows it.
While freshness is an important selling point for specialty coffee, remember: freshness is more like a bell curve; while there is an ideal time of consumption around seven to 10 days after roast, there is also a "less ideal, but still ok" period before and after.
Personally, I'd like to receive any freshly roasted coffee around five to seven days after roast, but if I see a particular bean I want to try that I can’t get in that window, I don't mind waiting two to three weeks. I'll just make sure to seal the coffee properly every time I open the bag and consume it within a week or so.
Since coffee is an agricultural product undergoing many complex processes, all coffee brews will be different. Instead of obsessing over a specific expired coffee date or date of roasted coffee, consider just enjoying the process of change while drinking coffee to see what — if any — differences in the brewed coffee you may notice.