No matter what method is adopted, if it is not taken properly, raw beans are easily infected with mold, absorb odor and become inferior beans. In other words, fine beans should be carefully selected, planted in good places, and the final processing technology and three processes should be perfected before they can be called fine beans.
Good coffee must choose ripe red fruit. As we all know, citrus, bananas, apples and other fruits are rich in organic acids. Immature fruit tastes sour and suspicious, and mature fruit tastes sweet and delicious, because the organic acid of fruit is converted into sugar. Coffee also needs to turn red, and it can only be picked when it is ripe. At this time, the sugar contained in pectin in the pulp and sheepskin glue layer completely penetrated into the beans, which greatly increased the fruity and sweet flavor of the beans. If coffee farmers want to save trouble, picking coffee together will make the taste of coffee sour, regardless of whether the coffee fruit is ripe or not, so fine coffee must pick ripe red fruits.
First, the sun method:
Sunlight method is also called natural drying method, because it uses natural sunlight to dry coffee cherries and raw beans. Because of the artificial and natural treatment methods used in the processing, the sun-dried beans look irregular and don't look good to sell. But its mellow taste and thick consistency are quite favored by some experts. The processing steps of the solarization method are as follows:
1. Bean selection: Put the harvested fruit into the water tank, the mature fruit will sink, and the immature and overripe fruit will float up and can be fished out.
2. Drying: expose the screened mature fruits in the square for 5-6 days until they are completely dried. At this time, the fruit turned dark brown and the water content decreased to 13%.
3. Shelling: The dried peel becomes fragile and easy to fall off, which can be removed by machine. The farms run by enterprises generally set up their own hulling factories, and the small farms are handed over to the processing center for processing.
4. Selection and grading: Fine farms will identify defective beans manually or by machines and pick them out and throw them away. Manual selection generally uses a conveyor belt with a width of about 1 m, and several female workers sitting on both sides pick out bad beans by visual inspection; In some excellent farms, it is even necessary to go through several selections until there are no defective beans. Machine selection rules use computer identification to eliminate defective beans. Then, there is the grading procedure, which divides coffee beans into several quality grades according to established standards. Good coffee enters the selected coffee market, and bad coffee flows into the commercial coffee market.
5. Polishing: hulling can only remove the exocarp and inner pulp. At this time, the silver film is still wrapped in the outer layer of the seed, and this film has to be removed by machine. Then, put the coffee beans into a 60 kg bag and wait for the price. The weight of bags in different areas is slightly different, and most of them are sacks, each bag is 60 kg; Blue Mountain coffee in Jamaica is packed in wooden barrels, with 30 kilograms and 70 kilograms.
Second, the half-sun method:
Because the quality of sun exposure is not easy to control, there is half sun exposure. Among them, there are several kinds of transformation, and the most commonly mentioned are two types: sun drying of puree and honey treatment. Some people say that honey treatment is a natural process of Puiped, and we don't refute it because the two methods are too similar. However, according to Los Lajones Manor, we think that honey treatment is a natural process change, because it hardly uses water.
Honey treatment method:
Introduction of honey technology of coffee honey treatment: honey treatment is one of the transformations of pulping natural technology, and almost no water is used in peeling process. After farmers remove the exocarp of coffee by machine, they usually sun it directly without rinsing. Raw beans are laid flat on the shelf. Because pulp and mucus are sticky, they will adhere to each other or to the shelf. Farmers must often stir them with shovels, which is very hard. The whole process takes 10- 12 days, and the moisture content of raw beans will drop to about 1 1%.
Honey treatment method hardly uses water, which avoids wastewater treatment and is most helpful to environmental protection. Moreover, coffee has a good flavor and is worth popularizing.
Third, the water washing method:
Water washing is the most popular treatment method at present, and it is adopted in almost all Central and South America except Brazil. The washed beans are beautiful in color and blue-green. The beans look neat and beautiful, and the coffee quality is the highest. Generally speaking, washed beans have good sour taste, bright feeling and clean and odorless fragrance, which is the most commonly used treatment method for fine coffee.
The treatment steps of water washing method are as follows:
1. Bean selection: soak the harvested fruit in a water tank for 24 hours. At this point, the mature fruit sinks, while the immature and overripe fruit will float up and can be removed.
2. Remove the pulp: remove the peel and pulp by a pulping machine, leaving only the coffee beans wrapped with the endocarp. At this time, there is a layer of mucus outside the beans, and the process of washing with water is to clean this mucosa.
3. Fermentation: Mucus has strong adhesion and is not easy to remove. It must be placed in the cylinder 18~36 hours to ferment and decompose mucus. There are two methods of fermentation, namely, wet fermentation and dry-wet fermentation. As the name implies, the former adds water and the latter does not. During fermentation, malic acid, citric acid, acetic acid, lactic acid and propionic acid are naturally produced in the tank. Interestingly, raw beans contain almost no acetic acid, but the fermentation process of water washing treatment can increase the acetic acid concentration of beans, which is beneficial to coffee flavor. These acidic substances can not only inhibit mold parasitism, but also mix some acid elves into beans (which is why washed beans are acid). However, it is necessary to take samples at any time to see if the sticky pectin on the pod is removed, and then decide whether to stop fermentation and take out the clean pod. Once it exceeds 36-72 hours, it may be over-fermented, producing too much fatty acid and butyric acid, giving off a stench. Moreover, adding too much acid to beans will also make coffee too sour. Chongqing is an inferior bean!
4. Water washing: The farm that uses water washing must build a water washing pool and be able to introduce a steady stream of tap water. When processing, the fermented beans are put into the pool and pushed back and forth, and the coffee beans are washed smooth and clean through the friction of the beans and the power of running water. Washing 1 kg coffee cherries with water consumes an average of 2- 10 liters of water, while 1 kg coffee cherries can only take 200 grams of coffee beans. It is difficult to bear this water-consuming method of getting beans in water-deficient areas.
5. Drying: After water washing, the coffee beans are still wrapped in the endocarp, and the water content reaches 50%. It must be dried to reduce the water content to 12%, otherwise it will continue to ferment and rot. A better treatment method is to dry it in the sun. Although it takes 1~3 weeks, it tastes excellent and is quite popular. In addition, some places use machine drying, which greatly shortens the processing time and makes the flavor of coffee not as good as that of dried coffee. Therefore, almost all farms that choose coffee let the sun dry raw beans.
Fourth, half washing
Not all producing areas can use semi-drying method. In the production area with heavy moisture, it is not easy to dehydrate and dry, but it is easy to parasitize mold. Therefore, the mechanical semi-washing method has been developed in areas with heavy humidity, which is convenient and water-saving.
Firstly, the red fruits and semi-green and semi-red fruits sunk in the sink are moved into a pulp screening machine to take out pectin, which does not need to be dried, let alone poured into the sink for fermentation. Instead, a little water is directly poured into the nearby pectin scraper, which can mechanically scrape off sticky pectin fragments, take out pods with smooth surfaces, and expose them outdoors until the water content drops to 12%.