- The best place to store coffee is usually in its original packaging.
- In general, whole-bean coffee stays fresh longer than ground coffee.
- To get the freshest coffee, look for a "roasted on" date on the bag.
- Visit Insider's Home & Kitchen Reference library for more stories.
When you buy a bag of coffee beans, the best thing you can do is drink it. Because here's an unfortunate truth: Coffee loses freshness over time.
The longer you wait, the more the aromatic compounds that give coffee its distinct flavor degrade. And no one likes their coffee stale and flavorless.
"Roasting coffee is like playing a note on a guitar. The flavor is strongest when it's freshest and fades over time," says Max Gualtieri, long-time barista, coffee roaster, and founder of Joules and Watts Coffee.
Storing coffee properly and consuming it fresh is key to maximum flavor. Here's what you need to know about keeping coffee fresh and tasting great for longer.
How long does coffee last?
There are a number of factors that determine how long coffee stays fresh. "The type of coffee, mostly varietal and roast degree, can influence the longevity of the coffee," Gaultieri says.
In general, moisture, heat, and oxygen impact coffee freshness. Storing your beans in a cool, dry place, and away from oxygen can make all the difference. Another big variable is whether the coffee is ground or not.
Whole-bean coffee vs. ground coffee
Buying whole-bean or ground coffee comes down to convenience, but it also has a direct influence on freshness. Whole beans stay fresher longer than ground beans.
Whole-bean coffee has less overall surface area than ground coffee, which means whole coffee beans are less exposed to oxygen, which slows down the oxidation process that results in stale-tasting coffee. Most specialty roasters recommend brewing whole coffee beans within the first two weeks after it has been roasted, but when properly stored it can last up to two months.
"Ground coffee starts to lose its zest as soon as you grind it," Gaultieri says. To keep your coffee as fresh as possible, brew it as soon as you can after grinding the beans.
"Once coffee is ground, it loses its flavor about sixteen times faster than whole-bean coffee." If your coffee is pre-ground, it should last about a week before losing its flavor.
Keep coffee stored in the original packaging
It's important to store beans in the right packaging to help with degassing and oxidation, which are the two main processes that change the coffee's flavor.
With degassing, carbon dioxide gas created in the beans during the roasting process escapes from the beans as they rest. As carbon dioxide leaks out of the beans, it carries the compounds that cause the flavor and aroma. After the carbon dioxide is released, it is then replaced by oxygen that seeps into the porous beans, which also leads to a duller flavor.
Exposing coffee to the air increases oxidation even more, making your choice of storage important. By cutting off exposure to the air, you can slow down the process.
The best way to store coffee is in its original packaging. "Many coffee bags are designed with a one-way valve that allows carbon dioxide to escape while preventing oxygen from entering," Gaultieri says. "Leave your coffee sealed in the bag, until you're ready to drink it."
If the original packaging doesn't have a degassing valve, or you prefer to transfer the beans to another vessel, make sure to use an opaque, airtight container.
Keep coffee away from heat and moisture
Heat and moisture also impact the freshness of coffee. It may seem convenient to keep your coffee on the kitchen counter, but there's a lot that can go wrong. Cooking, for example, can produce a huge amount of moisture and increase the temperature.
"You want to keep it in a cool, dry place because even small increases in the temperature can have a dramatic effect on the degassing rate," Gaultieri says. "Moisture also advances chemical and physical changes in the coffee." Those changes can impart unwanted flavors in the coffee, like sourness or rancidity.
Keep coffee out of sunlight
Storing your coffee in a sunny area can have a detrimental effect on the freshness of your coffee, especially if it's kept in a clear container.
"Storing your coffee in a clear container in direct sunlight basically causes the greenhouse effect," Gaultieri says. "Just like a car on a hot sunny day, the light enters the jar and heats up the contents of the container, but the container keeps all of the hot air from dissipating."
Avoid this by keeping your coffee in an opaque container or in its original bag and store in a cool, dry place.
Grind your coffee right before brewing
If you're dedicated enough to have your own coffee grinder, the best way to enjoy coffee is to grind it right before brewing. Grinding your coffee agitates and exposes all the aromatic and flavor compounds in the beans to the air. This speeds up the processes through which coffee deteriorates, so to avoid the coffee going stale faster, brew it immediately after grinding.
How do I know if coffee has gone bad?
Coffee doesn't go bad in the same way that fruit, dairy and meat does, but over time the flavor changes dramatically.
If stored improperly, aromatic compounds that give coffee its scent and flavor deteriorate over time, causing the coffee to taste stale, flat and dull. When it reaches this point, the roasty, chocolate and caramel notes often present in coffee are muted and an unpleasant musty flavor becomes noticeable.
To find the freshest coffee while shopping, look for bags that tell you what date the coffee was roasted on, not a "best by" date. "A roasted on date is a more accurate reading of the life span of coffee," Gualtieri says. "You know exactly when the clock started." Mass-produced coffee often has a "best by" date on the bag, but typically you have no way of telling when the coffee was actually roasted.
Insider's takeaway
The easiest way to ensure your coffee tastes great every morning is to buy it fresh and store it properly. To slow the processes that degrade the fresh flavors of coffee, keep your beans in a sealed, opaque container away from heat and moisture. If you have your own coffee grinder, grind your beans right before brewing to make sure all the aromatic and flavor compounds find their way into your cup.