Sunday, November 18, 2007

New Harvesting Techniques

Flickr photo by : thephotomat

Today i read this interesting article in the C&C I about coffee beans harvesting.
For you the first and most interesting part :

In many parts of the world the need to control production costs is causing harvesting to be less and less selective. On the other hand, the quest for ever higher quality requires that cherries with different degrees of maturation be pulped separately, suggesting that quality - and profit - can only be maximized by using the right combination of harvesting and processing systems.

The dilemma is particularly obvious when it comes to certain types of coffee, such as Yellow Bourbons.
Yellow Bourbon only started to come to the attention of the specialty coffee industry after the use of pulped natural (semi-washed) post-harvest processing systems became widespread in Brazil. the immature cherry separators used in this relatively new process make it possible to separate unripe cherries from the ripe ones, which cannot be done visually with Yellow Bourbons.

The immediate impact was a greatly improved cup with features that repositioned Yellow Bourbon in the market and attracted growing demand and price premiums. New areas are now being planted with Yellow Bourbon, in contract with former years when the variety did not receive much attention and production was falling.
Increased rejection of fully washed coffees from many origins due to astringency in the cup is often a result of the phenomenon described above, in relation to red rather than yellow coffee varieties.

Astringency is caused by compounds that precipitate salivary proteins on the tongue. It may be caused by unripe or only partially ripened cherries that are pulped together with fully ripe ones. Whereas unripe cherries can be visually separated during harvesting or afterwards, cherries that are only partially ripe cannot. They are pulped together with the fully ripe cherries and impart astringency to the end product.
The problem can, however, be solved by new technology that pulps only fully ripe cherries and separates all of the other cherries, whose degree of maturation is less than optimal. Growers who have used this new technology in recent years have not only sold their coffees at premium prices, but won quality awards and competitions.

The quest for an ever higher cup quality has shown that the visual criteria used in selective picking are not necessarily sufficient tot ensure that cherries are fully ripe. This can only be ensured by criteria other than visual identification of the colour of the coffee cherry. The availability of this new technology opens up interesting possibilities for improving the quality of coffee and - potentially- reduce the cost of harvesting coffee in an era when labour is becoming increasingly expensive.
Today, harvesting systems and on- farm processing technologies have to be compatible with each other in order to maximize benefits with the least cost.

On average, a person stripping coffee harvests 3-5 times more coffee than a person selecting mostly ripe cherries. Handheld harvesters enable a picker to harvest 20 times more coffee than a person performing selective harvesting. In contrast, a large harvester on wheels can pick up to 500 times more coffee than a single person resorting to selective harvesting.
But the problem is that not all of the above-mentioned techniques can be applied in coffee producing areas where coffee trees have ripe and unripe cherries, cherries under development, flowers and flower buds at the same time on different branches or at different points of the same branch.

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