Coffee processing method Wet

Processing Arabica coffee is a complex and demanding task. It requires knowledge and experience to be able to produce high quality products accepted by the world market. Of course, quality starts from the orchard through the selection stages, disease control and harvesting only ripening fruits. However, even with proper application of the correct practices in the orchard, optimum practices in processing and postharvest handling are required to maintain the natural properties. The quality of coffee is sold at high prices in the world market.

We would like to introduce to the coffee devotees and readers who are interested in wet processing methods, the article is largely derived from the contributions of Ken Calvert, Coffee Processing Expert High level.

International traders and roasters are always demanding and willing to pay high prices for good quality coffee. For their part, consumers are also willing to pay high prices to buy good quality coffee.

In general, Arabica coffee is processed in a wet, high-priced fashion on the world market because of its taste characteristics. However, coffee processed in this method requires a lot of skill, care and labor to produce high quality products.

To get the best quality and price, processors need to know the potential of coffee in the area and then decide on the best way to process it. According to many studies, Arabica coffee grown at higher altitudes will provide better natural qualities. Location of Arabica coffee in northwest Vietnam is above latitude above 20 latitude. It compensates for some of the weakest aspects of altitude. If the globe is spinning, this latitude equals the latitude of the world famous Kona - Hawaii. Other factors affecting the quality of coffee include climate, soil and seed.

However, wet processing is the most important factor in making high quality Arabica coffee. Processors need to master the best processing techniques to take full advantage of the quality of the fruit. This will prevent coffee quality deterioration by improper processing techniques.

Processing methods "Wash" and "Do not wash"

In the world, the terms "washing" (Spanish "Lava do") or "washing" are used to refer to good quality Arabica coffee, which is made by wet methods. The term "washing" is used for the processed coffee that has been fermented, including the washing after fermentation. The term "semi-wash" or "semi-wet" is used for brewed coffee and then dried without fermentation. The term "washing wash" often confuses people because they think of different processing techniques. Coffee processed by washing method has higher economic value than unpolluted coffee because it has higher acidity, lighter body and better quality of cleansing.

The second step is to pick the pick, picking only the red ripe fruit. Ripe fruit can be run smoothly through wet processing stages and will give the aroma during roasting. This will be appreciated by customers.

Green fruit will have the smell of grass or odor, reducing the quality of products. The most dreadful is that the fruit has a black core that has dried on the tree or fallen but still picked up. Avoidance of brown seed, rotting or fermentation is caused by the delay from picking to processing. Fresh fruit should be delivered to the factory for processing as soon as possible, avoiding fermentation.

The selection of red ripe fruits in the collection process takes more steps but will produce high quality products. It is important to avoid picking because it will not categorize ripened fruits and fruits.

Fresh fruit picking

At the receiving facility, processors should pour fresh berries from the packs and take quality assessment samples to ensure that the coffee beans are delivered in good quality. If there are too many green and / or fermented / rotten fruits (more than 10% to 15%), this coffee should not be processed as it will damage the entire batch of processed products. The classification of these fault particles in the later stages takes time, just good and not necessarily effective. Fresh fruit is poor quality will later be discovered by customers during roasting and tasting!

Processors need to remember that the cost of any defect is equal to the quality of the grain in the transportation, storage and processing stages. However, when the price of the shipment is very low. Processors should avoid these errors as soon as possible during processing, which means removing the fruit immediately during the process.

Filtration and preliminary washing

Processing time in Vietnam often falls in the rainy season because fresh fruit often has a lot of sludge clinging to the plant. Soils and impurities such as sticks, leaves and stones need to be removed before being introduced into the milling machine to prevent the introduction of machinery. The best screening is to put on metal screens and have a flush.

In the next step, the fresh fruit should be poured into the siphon tank to remove the floating fruits and other light impurities mixed with the ripe fruit. This technique uses the difference in the proportion of fresh coffee: the ripe fruit will sink and will remove the blown fruit easily.

Chopped

Many Vietnamese processors use fresh grading machines before hulling. Experience has shown, however, that the rate of green berries is still high. Unfortunately, the increase in quality over quantity is still very common.

Cultivators and shredders should be serviced regularly and all broken parts must be replaced. Regularly check the operation of machinery by checking the product.

Due to overloading or in milling machines with small rods and stones, the blades are worn out. This can damage coffee beans and coffee beans. Once the protective cover is damaged, the kernel is exposed to the external environment and therefore tends to break down during the drying and storage stages. Do not damage the paddy rice and kernel while rubbing.

 Pre-filter and wash the coffee

Ferment

Natural fermentation is a biological method to remove the viscous residue from rice husks to prepare for drying. In the process of complete washing, the coffee is completely rinsed into the fermentation tank. And soak for about 12 - 36 hours. During this time, the enzymes of the pectin-degrading microorganisms will develop the wet and damp conditions of the paddy coffee to heal and convert the monosodium glutamate into acid. The removal of the viscosity around the grain is closely related to the increase in the acidity of the medium during fermentation. Therefore, the fermentation tank needs a light acid (at pH 4.5-5) to completely remove the viscous during fermentation. However, too much acid should be avoided.

Wash the coffee

After completely eliminating the viscosity during coffee fermentation should be washed to remove the by-products of the fermentation left over will discourage the coffee and paddy is a good foundation. mold growth. Therefore, paddy coffee needs to be cleaned before processing.
Finished washing of coffee beans grain will be carried out in the sun or dried by the machine. Sun drying is technically not favored as it is simple and inexpensive. However, not only that, the ultraviolet rays of the sun can bleach chlorophyll in the seeds and reduce the smell and the smell of grass in the coffee. Surveillance of sun drying should be monitored carefully as the location of exposure and weather will have a significant impact on the process. Avoid getting wet due to rain. Drying on drying tables is usually optimal because of the maximum reduction of bad factors affecting rice grain such as hybrids and contaminants in the soil.
(Collect)