by Miron Huhulea

Created on: March 17, 2009   Last Updated: March 18, 2009

The first step in coffee harvesting is picking. A coffee plant will start to produce flowers three to four years after planting, with the first harvest of coffee cherries usually possible after about five. The cherries, which look a little like cranberries or other hard tree berries, are ready to be picked when they ripen from green to red.

Coffee beans are usually picked by hand throughout the coffee growing regions of the world. They are either strip picked, where at harvest time all the cherries are stripped off the plants, or, in the case of finer arabica and plantation coffee beans, selective picking will be used, where pickers peruse the plants about every week or so and pick only the cherries that are at the peak of ripeness.

Green or unripe berries, because of their lower oil and higher organic acid content, can have a sharp bitter or astringent odor and flavor, and are usually found in Coffea robusta (the cheaper and less flavorful cousin of C. arabica) and mass consumption coffee blends (coffees you would find at the supermarket).

After picking, the next step in the harvest is separating the bean (or seed) from the fruit surrounding it, which is not as easy as it sounds because the fruit it quite pulpy and sticks to the bean.

In the ferment-and-wash method, the beans are left to ferment for twenty-four to thirty-six hours, and this short fermentation process breaks down the fruit around the beans, which are then washed with large amounts of water to separate them from what is known as the mucilage layer.

The dry process, also called unwashed coffee, is also the oldest method of preparing coffee. Ripe berries are separated from unripe and also from other plant material an dirt by hand using large sieves, in a process called winnowing.

After winnowing the beans are dried in the sun for about a month, so that the fruit becomes leathery and is ready to fall off, and are hulled by machine in a final step that leaves nothing but the bean. The hulling step must also be performed on wet-processed coffee, where in this case it removes a crumbly parchment skin.

After hulling the green (unroasted) coffee beans are cleaned and sorted, so that any material debris introduced during drying is removed; this is usually done by a series of machines.
In high-quality preparations the coffee is then sortedby color to separate discolored and defective beans from the sound beans, and this step is usually performed by hand.
What you'll have after the picking, processing, and milling (hulling, cleaning and sorting) is a green coffee bean that is now ready for roasting - the final step in processing that gives coffee its distinctive flavor.

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