Ever wondered where the concept of aged coffee did come from? Historically it is traced back to the 16th century where the coffee shipments used to travel from the port of Mocha (now known as Yemen) all the way to Europe. It took several months for coffee to reach the destination from its point of origin. Sea voyage meant green beans were exposed to plenty of salty and humid environment while they travelled in ships.
When Suez Canal became operational in 1869 however, the route was shortened and Europeans were supplied with fresher crop. But people were accustomed to the taste of old coffee and it was then when the idea of deliberately aging the beans emerged.
Aged and old are two different words in terms of coffee. Old coffee is stale, woody and can even be rotten. When green beans are “aged” hastily and negligently in warehouses near the sea port or in an environment which is hot and humid in general the product is not a true “aged coffee”.
While there are no standard outlines on how coffee should be aged, coffee experts agree that quality aged coffee is aged at high altitude to avoid major fluctuations in climate and high humidity. The green coffee is aged while still in parchment. That way the least deterioration occurs in coffee over time. The bags are constantly and carefully rotated in warehouse where it is aged. This way all bags are evenly aged and chances for them to develop mold decreases. The whole process can take up to three years.
Since good aged coffee requires time and honest effort it is definitely something not easily found. It is risky too, after all, what if the lot the producer had been working on, for a whole year or two turns bad? In a good aged coffee the acidity is very much reduced, the cup gains full body and hence can feel syrupy. As far as aroma is concerned, coffee beans are sensitive to odors around and pretty good at catching them. So a baggy taste is simply to be expected. Woody is another note that aged coffee catches in its flavor. All in all flavors can be compared to stale but NOT dirty.
If there is dirty taste it isn’t “aged coffee” probably some “old crop” that has been sitting in some warehouse, unsold for long time and the vendor decides to deceive the customer calling it aged.
Not all coffees age well. As a rule coffee is aged while still unroasted and not hulled (contained in parchment). Moreover coffees that are naturally more acidic cannot pass the cupping session for aged coffee as the baggy taste will be too obvious in their cup because the acidity degrades seriously over time. But a milder coffee that carries earthy notes naturally probably will pass. Because the baggy taste will not create a contradictory character once the coffee is aged. Not that the baggy taste is not going to be obvious in naturally mild plus aged coffee, it is just the tastes will blend the baggy falvor.
Last but not least; aged coffees are preferably roasted very dark to mask the stale flavors as much as possible. But IT IS that stale and smoky flavor that aged coffee enthusiasts like about it the most.