Storage and transportation of coffee

Storage and transportation of coffee
Ideally, coffee is bagged with a standard moisture content of 12%, in the country of origin, and it is kept below 70 degree F until close to the time when it can be placed in a ship.

Some coffee is also stored in silos, but this is usually just for a few days.

The coffee beans need to be stored at low temperature once on-board ship, and away from any storing smelling cargo.

Ideally, the journey would be as short as possible and any subsequent movement of the beans would be at 7% and low humidity.

This is quite difficult to achieve in practice and the risk of developing molds is high.

Another risk is that compounds will be leached or volatized from the green coffee beans so that they will not yield a pleasing beverage.

Green coffee beans are reasonably stable for one year at 70 degree F and 40 to 60% relative humidity.
Storage and transportation of coffee

The Chemistry of Roasting Coffee

The Chemistry of Roasting Coffee
Nothing affects coffee favor more than how the green, “raw” beans have been roasted. If to brew raw beans, the result would not possess any flavors recognizable as coffee.

Roasting is the key stage, whereby the characteristics taste, aroma and final flavor of the beans is developed.

The length of time of the roasting process also determine whether the coffee will end up being a “cinnamon,” “city,” espresso,” or “dark French roast.”

In simplified terms, coffee is describes as “light,” “medium,” or “dark” roasted.

In the roasting process, heat from and external source is applied to the raw coffee beans in large vats or drums, spinning and heating them evenly at temperature reaching up to 550 degree F (290 degree C).

The heat essentially creates chemical changes in the physical structure and composition of the beans.

Water evaporates from the beans, starches convert to sugars and the sugars caramelize. The beans increase in size by 25 to 35 percent. They begin to pop, much like popcorn.

They lose 18 to 22 percent of their weight, mostly through this evaporation. The caffeine content, however is not affected by these changes.

Gradually, the green beans turn a yellowish color, then darken to a deep rich brown. During this color change, a number of chemical reactions occur, causing the beans’ sugar and proteins to interact with each other.

It is these changes, and the release of caffeol, or coffee oil, that are essential in bringing out the flavor and aroma of the beans.

The darker the beans, the more oil they produce.

Great care must be taken as the process nears completion, to ensure that the beans are not burnt.

Flavorful acids from as the beans turn into a medium dark roast. As the roasting progresses toward a darker roast, these same acids will now begin to break down, and the sugar components will start to caramelize.

A darker roast has more body and an intense richer flavor to the palate, that is why espresso beans are characteristically low in acidity, rich in body, and sometimes caramel like.

After this monitored roasting process, the coffee beans are rapidly cooled down by jets of cold air, thereby seeing in all flavor and aroma that the heated air has brought to life from the dormant green beans.

The lighter the roast, the more flavor acids, resulting in interesting flavors and sparkle. Lighter roasts are lighter in body because the roast has not produced caramelized sugars or caffeol.

Medium roasts have less acidic snap: they are richer, with a more rounded flavor. Here, coffee oils begin to appear.

At the dark roast stage all acidic tones disappear; the beans are oilier, there is a definite bittersweet, chocolate flavor, the brew is rich, and full in body and texture.

An interesting note on roasting as it pertains to caffeine content: The darker the roast, the less caffeine content it will have. Higher, longer roasting temperatures eliminate more caffeine from the beans than will a brief, cooler roast.
The Chemistry of Roasting Coffee

Harvesting Coffee

Harvesting Coffee
A frustrating fact for coffee growers is that coffee cherries ripen at different times on the same tree.

One branch can simultaneously hold blossoms, green fruit, half-ripe berries and rosy red cherries.

That’s why on most farms, the fruit of the coffee is plucked by hand, just as has been done since time immemorial.

Pickers typically visit each tree three or four times in a season, picking only the ripe beans and leaving the green beans to be harvested at a later time.

Even some a good picker will harvest two hundred pounds of the fruit in one day.

But not all coffee picking is accomplished by hand. On large, modernized farms, common in Brazil, a harvesting machine is used to strip the tree of its fruit.

Although these machines leave the coffee plant intact, they remove all the loose cherries-both those that are ready for roasting and those that are not yet ripe.

But because such plantations operate on a massive scale, they are nevertheless able to yield a profit.
Harvesting Coffee

Industrial Processing of Green Coffee Beans

Industrial processing of Green Coffee Beans
Four methods of industrial processing of green coffee beans are used:

*Roasting, an essential process to develop coffee’s aromatic properties

*Grinding

*Percolation followed by dehydration to obtain soluble coffee

*Decaffeination


Prior to processing, green coffee beans are clean and dusted by pneumatic machines, then stored in a partitioned.
Industrial processing of Green Coffee Beans