The Miracle of the Bean

Discuss flavors, brew temperatures, blending, and cupping notes.
User avatar
Team HB
Posts: 10484
Joined: 19 years ago

#1: Post by cannonfodder »

The Miracle of the Bean
Photos courtesy of Chris Holliday, I once had a farm in Nicaragua

We discuss machines, thermal group models, water debit, dosing, distribution, tamping, grinding and may other details. However we rarely discuss the one little miracle that makes our entire obsession possible, the diminutive coffee bean. Let's take a moment to reflect on this wonder of nature.

Lore suggests that coffee was discovered by an Abyssinian goat herder by the name of Kaldi. One day while tending to his herd, he noticed the goats had become rather energetic. Upon further observation he noticed his goats eating the red cherries of a small bush. Intrigued, he picks a few of the bright red cherries and consumes them. Soon he finds himself energized by the strange fruit. Old Kaldi is the recipient of the world's first caffeine buzz.

Inspired by these events, he picks some of these wondrous fruit and returns to his village where he consults with the Wiseman. Having recalled the account to the Wiseman, the cherries are deemed evil and tossed into the Fire. Moments later he is drawn back to the fire by the aroma of the roasting beans. The Wiseman retrieves the beans from the fire and places them in water to cool. Later he tastes the water the beans have been steeping in and finds the elixir enjoyable. The coffee revolution has begun.

The Coffee Arabica tree migrated through Eastern Africa where it still grows wild. Eventually it was cultivated in the Arabian Peninsula and into Yemen and Java. From there it spread through the world.

Once the beverage reached Europe it was almost snuffed out. It seams that the predominant Catholic population had deemed the beverage "the Devil's brew". Thankfully, Pope Clement VIII had already learned the virtues of the beverage during his travels abroad. The pontiff blessed the holy bean and it spread across Europe as a Christian beverage.

Espresso is a relatively recent development having its origins around 1822 in France. The Italians took the process and perfected the espresso method of brewing the holy bean. In 1946 Achilles Gaggia perfected the first pressurized espresso machine. Scoffing at 1822 as a recent development aren't you? Well keep this in mind, old Kaldi discovered the bean around 800-900AD.

Onto the Bean.

Our Coffee Arabica bean starts life just as any tree, a small seedling. It takes 5 to 7 years for that little seedling to reach maturity. During that time the farmer has to take great care. Arabica trees are very slow growing and delicate. Once that tree reaches maturity it flowers and produces our coffee cherry. Your average Arabica tree produces a scant pound of final product. Do the math in your head; how many trees' output coffee do you consume in a year?

Once that tree produces its fruits, the real work begins. Those cherries are even more fragile than the tree. A growing cherry is easily damaged. Something as innocuous as a heavy thunderstorm can destroy an entire year's crop leaving the farmer penniless. Many farms have been swallowed up by the jungle because of one year's failed crop.

Once that cherry reaches maturity they must be hand picked. The trees are too delicate for machine harvesting, the typical terrain too rough for mechanical harvesters, and all of the cherries are not ripe at the same time. Most crops are picked two to three times in a year.

Those ripe cherries are picked by hand regardless of the weather. These harvesters work long days picking baskets full of cherries for pennies a day. Truly back-breaking laborious work.

Once those cherries have been harvested they are hurried off to a processing facility. At this point the cherries are treated one of two ways. They are either wet processed or natural(dry) processed. At any point in the process the harvest can be ruined.

In the case of the wet processed coffee, the harvest is hurried off to the processing mill. The problem here is that wet processed coffee has to be processed quickly. Once picked the cherry starts to ferment. While fermentation is desirable at certain stages in the process, it is disastrous if it occurs too early. How quick can a harvest go bad? I'm glad you asked that! Say the farmer's tractor gets stuck in the mud on the way to the mill. They have to find someone that can pull or dig them out. A day too late and they have a trailer full of compost. Get a flat tire on the way to the mill? Sorry, compost time. Line at the mill or a broken depulper at the mill? You guessed it, compost.

Now assuming they make it to the mill, the beans are about to go through a process that would make the inquisition look placid. First the beans are dumped in water tanks. Any overripe cherries, leaves, sticks etc float to the top and are skimmed off. Next the beans travel down a water slide to be deskinned. Sounds painful, doesn't it? The cherries travel into a machine that resembles a tomato peeler. Once this medieval device does its job, the seeds, still covered with their pulp, go into sizing drums.

Once through the sizer, the beans dump into holding tanks. Now here is where the alchemy starts. The beans are left in their pulp to ferment. Timing is everything. If they ferment a couple of hours too long, time for the compost pile. Once the master processor deems the lot ready, they are once again sent down a water channel to remove the now soft and ripe pulp. Now the bean can be dried and packaged.

If the processor wants natural processing, there is even more alchemy involved. Once the beans are harvested they are transported to the mill. The whole cherry is dried. The harvest is dumped onto drying patios. A worker must rake out the cherry evenly on the drying beds. Too thick and they will dry at different rates. The crop must be turned on a regular basis to promote even drying. Once again, this is a manual process. A worker uses a wooden rake to stir the cherries. Oops, forgot to check the weather forecast, the outdoor drying beds just got rained on. Time for the compost pile.

These outdoor drying patios are cheap. The sun does most of the work; however it is only practical in areas that do not receive a lot of rain. That is why most of the African beans are patio dried. The drawback is that the harvest is open to all kinds of contaminates. Blowing sand, rocks and bugs. That is why most coffee roasters run their greens through a destoning machine.

In place of patio drying there are artificial drying beds. These are expensive and hence not commonly used. Among these other forms of processing are the solar bed. Essentially it's a small ventilated greenhouse. The cherries are thinly spread on these tables which are then moved into the sunlight. This process is much slower than patio drying but in wet climates there are not many other options.

In addition to the solar table there is the solar bed. This uses a large sheet of plastic with a canopy over it, a chimney in the back, and a small opening in the front. As the cherries heat, the air rises out of the chimney. As the air evacuates in the rear, fresh air is drawn in through the front creating a pseudo wind tunnel. I believe they even have gas fired drying systems.

Once the processor deems the crop ready, all of these cherries are transferred to a hulling machine. This device is essentially a steel screen with a big auger down the middle. If you have ever seen a juicer or meat grinder, you know what this looks like. The cherries are dumped into a hopper where the auger draws them through. As the augers spirals get tighter, the bean is squeezed out of the hull and exits at the end of the auger.

Once the bean and fermented pulp have been separated, the beans are dried, further sorted and stored. At any point of the drying process the crop can go bad. Too long in the sun and the bean over ferments; raked improperly and the wet spots will mold. Once again timing is everything.

Once the dry or wet processed beans have had their final drying and sizing some are sent off to a polishing machine. This device mills off the silver skin or "parchment" from the beans' surface. Not all processors take this final polishing step.

Now the greens are bagged and tagged and sent off to your local roaster via a container ship. Unfortunately, many a good crop have gone bad in this phase. Subjected to the ocean air and very high temperatures (remember these are steel containers on the deck of a ship in the middle of the ocean). The entire container of greens can go bad. I have even heard of containers being lost overboard.

This just scratches the surface of the coffee processing. It is a miracle that this delicate tree manages to produce the exquisite fruit that graces us with the coffee bean. This tiny bean has grown to become the world's dominant beverage. The only liquid to outrank coffee in world consumption is water. So grind that roasted bean and enjoy your cup of Joe, but remember what it took to get that one diminutive seed from the tree to your grinder.

Dave Stephens

User avatar
Posts: 3646
Joined: 19 years ago

#2: Post by peacecup »

I haven't even had time to read this post, but I can see that its a great one. We do spend far too much time talking temperature and far too little talking taste. I'm looking forward to having time to read this in full. Here's to Mother Nature, and the all those who bring us coffee beans. Its a labor of love.


LMWDP #049
Hand-ground, hand-pulled: "hands down.."