Each year $19 billion of exported coffee pours into eager, thirsty markets globally, states the fact-checker PolitiFact.com.
For me, brewing a world-class cup of single-origin at home is practically a new breakfast ritual. Bean quality and freshness are central to a great cup of joe.
This article covers coffee bean basics, including proper storage and expiration time frames.
The Freshness Countdown
Coffee beans are perishable and begin degrading almost as soon as harvested. Coffee beans are not beans; they're the seeds of the cherry-like fruit that grows on the coffee tree.
There are as many as 100 different species.
The two species most widely used for commercial sales and brewing are Coffea Arabica and Coffea Robusta.
Arabica accounts for 70 percent of all the coffee sold, brewed, and drank in the entire world, states the National Coffee Association (1).
Coffee trees grow best in the Coffee Belt, a region located just north and south of the equator.
This 'belt' encompasses roughly 50 countries. Both species grow best in temperatures of 59 to 75 degrees Fahrenheit, at altitudes of 2,000 to 6,000 feet, with at least 60 inches of annual rainfall.
Coffee seeds (beans) attain their complexions through roasting. Before roasting, they are green.
Each state of roasting changes the shelf life of a batch of coffee beans. This affects the amount of time that coffee beans remain fresh.
Green Coffee Beans: Freshness Timetable
Green beans, which are becoming more popular and available for retail sale, are extremely hardy.
If stored in a burlap sack, in a cool and dry place, green beans remain fresh and usable for up to two years.
Bounce tips: Ideal storage conditions include a burlap sack made of cotton, ambient humidity of 60 to 75 percent, and overall temperatures of 55 to 80 degrees F.
Roasted Coffee Beans: How Long do They Stay Fresh?
Roaster's guidelines and roasting dates often appear on the coffee product's packaging, especially if you purchase coffee from speciality roasters and small-batch purveyors.
As a general rule, it's best to grind and consume your roasted coffee within four weeks of the roasting date.
If you snag your coffee beans off the supermarket shelf or in bulk from a place like Starbucks, only grind what you intend to brew and drink in one sitting.
Again, try to grind and drink all of your whole beans within four weeks.
Roasted beans stored in an airtight container, in a cool, dry place, stay fresh for up to six weeks.
Experts agree that freezing whole beans, and even ground coffee, lengthens coffee's freshness timetable.
However, freezing is only effective at preserving coffee bean or ground coffee freshness if you use only what you intend to brew, never allow the coffee to defrost.
Bounce tips: Never return unused, defrosted portions back to the freezer.
What Causes Coffee to go Bad?
Coffee seldom goes so bad it's undrinkable. Naturally, you or someone you know may have nightmare examples of coffee stored and forgotten in the fridge, only to be unearthed a year later covered in mold.
Those are very extreme examples.
Generally, it's the combination of time and exposure to oxygen that degrades the freshness of coffee beans.
The more time coffee beans are exposed to oxygen, the more quickly and completely they degrade.
Coffee beans contain oils that the roasting process brings to their surfaces. These oils carry most of the fat and flavor. As the oils degrade, your coffee beans lose most of their flavor.
Bland or off-flavor is the most potent side effect of spoiled coffee. Since the experience of flavor concerns your senses of taste and smell, a coffee may taste bland but smell fine and vice versa.
Other times, your coffee beans may have no smell at all. The absence of smell indicates that your coffee beans are no longer fresh. They are still drinkable, and you may choose to grind and brew them anyway.
Coffee Freshness and "Blooming"
If the coffee beans you purchase don't include roaster's guidelines or a roasting date, here's a simple home test you can do to ascertain a rough confirmation of freshness.
Roasting traps high amounts of carbon dioxide (C02) within coffee beans, states the Huffington Post (2).
This CO2 evaporates and escapes over time, a process that industry insiders call "degassing" (3).
This is why freshly roasted coffee from respected purveyors often sells in special packages that allow CO2 to escape without permitting oxygen to enter.
Fresh coffee tends to degas over time. This degassing phase happens very quickly when you introduce freshly roasted, ground coffee to hot water.
This quick escape of gas causes a "bloom." A bloom occurs when grounds puff up into a dark nebula or floral shape in the hot water.
The larger the bloom, the fresher the coffee. The test is imprecise, but it helps to let you gauge freshness at home.
Older beans tend to produce a weaker bloom or no bloom at all.
Coffee beans don't go bad, per se, but they can lose their flavor and aroma over time.
Roasting coffee beans brings their oils to the surface. Coffee bean oils hold most of the flavors and aroma.
As coffee beans age, oxygen and time degrade their oils, which diminishes their quality.
They may still be drinkable, but they won't be as palatable. Do you have any other coffee bean freshness tests?
What nifty storage tips do you know of that I didn't mention? Please share, or enclose any questions.
In closing, adhere to these simple steps for optimal coffee bean freshness:
If you don't have roaster's guidelines or a clearly labeled roasting date, do your own at-home "bloom" test to approximate freshness.
My name is Kathy Gallo, Editor of Ag Ferrari food blog. The guide you find here is designed exactly for you, and it is our hope that you find it not only interesting but also actionable.