The specification and grade of coffee beans basic knowledge of coffee

Small and round dark brown coffee beans, quietly emitting a fragrant fragrance in the grinder, injected into the cup showing the beautiful color of amber, these are the three very deep impressions of coffee.

As you explore the history and beauty of coffee, you can also see the coffee trees that are caressed by the tropical sun and whose leaves twinkle. It has a small white flower similar to jasmine, its fruit from green to yellow-green, and finally to red, coffee beans are the seeds in its fruit.

Moreover, if you go to the coffee bean refinery, you will surely see the red pulp called coffee cherry and the fresh and green coffee raw beans with the endocarp and silver skin removed. These are the coffee beans for export.

At present, there are about 60 coffee-producing countries, most of which are located in areas with an elevation of 300 to 400 meters, and sometimes coffee trees are cultivated on highlands with elevations of 2000 to 2500 meters, but those planted on slopes above 1500 meters above sea level are said to be of better quality.

The most suitable conditions for the cultivation of coffee trees are areas with an average annual rainfall of 1500-2000 mm and an average temperature of about 20 degrees.

Coffee is an evergreen plant of the Akanaceae family. If it is wild, it can even grow to more than eight meters. However, in the farm, the height is cut to about two meters to ensure the quality of coffee beans and facilitate management.

At present, the main tree species planted are Arabica species, Robusta species (Carneva species) and Liberika species. It can be subdivided into dozens of varieties, which will be distinguished in production, circulation and trading.

Even in the same producing country, it will have a subtle influence on the flavor and quality of coffee beans and produce their own characteristics because of the differences in climate, altitude and soil quality in different regions. Therefore, according to the variety, origin, brand, there will be different attributes; therefore, it is impossible to describe the characteristics of a country's coffee beans in one sentence!

Specifications and grades of coffee beans

a. Washing / non-washing

Washing type: in the sink, after rubbing with water and utensils, the pulp and colloid are removed and dried, which is called washing coffee bean with uniform quality.

Non-washing type: after the sun is naturally dried, the pulp and peel is removed by a sheller, and its quality is unstable.

b. Flat beans / round beans

The fruit of coffee consists of two oval seeds opposite each other. The connecting side of each other is a flat joint, which is called flat bean. But there is also a round seed called a round bean, which tastes no different. Ripe and red coffee cherries have multiple structures. In the middle is the predecessor of the coffee bean, the light green seed.

Generally speaking, the fruit of coffee is made up of two oval seeds opposite each other. The side that connects with each other is a flat joint, so it is called flat bean. But some are made up of a round seed, and its taste is no different.

c. The size of coffee beans

Filter number (mesh no.) Coffee bean size

Flat bean

20-19 extra large

18 big

17 quasi-big

16 ordinary

15

14 small

13-12 extra-small

Round bean

13-12

11 quasi-big

10 ordinary

9

8 small

d. Altitude

According to the elevation of the cultivated land, it can be divided into three, four, seven and other grades. Generally speaking, the quality of highland beans is better than that of lowland beans, and the price is higher because of the increase in freight.

Grade name elevation (m)

1 special grade beans 1.500 ~

2 first-class beans 1.200 and 1.500 ~

3 medium beans 1.000 and 1.200

4 special water washing beans 9001.000

5The beans are washed with good water 760mm 900.

6 special water washing beans 610-760

7 excellent water washed beans ~ 610

e. Quality

According to the statistical method, the type and quantity of dopants contained in a certain amount of samples are converted into percentage "defect number", and the basis for determining the quality class is that the smaller the defect number is, the higher the quality is.

f. Taste

Brazil, Haiti, Kenya, say and other countries all have their own taste testing methods, which can be exported only after taste testing.

Arabika species and Robusta species

Arabica and Robbita species account for about 2/3 of the world's coffee production. It is not suitable to grow in areas with high temperature, low temperature, more rain and less rain. The bean is oval shoulder flat, which is characterized by strong fragrance and good quality.

Robusta is bitter but not sour, and the flavor is not very good, so it is suitable for making mixed coffee. Mixed with the right amount of robusta in Arabica, it is usually used to make iced coffee, instant coffee and canned coffee. It is characterized by growing in lowlands and strong disease resistance.

The quality and output of Liberika are not good. Most of them are exported to Europe, but not imported to Japan.

New crop (new bean) luster is light green, with a unique sour taste and coffee aroma, very distinctive. (right)

Past crop (annual bean) has a yellowish color with a light green color, which is sour and milder than the new bean. (middle)

Old crop (multi-year bean) is yellow due to water loss, slightly sour and ordinary in taste. Usually used as a blend and brewed into canned coffee. (left)

From harvest to shipment

After the fruit is harvested, the outer skin, pulp, endocarp and silver skin should be removed before shipping. There are two kinds of methods: drying (also known as natural or non-washing) and washing. The drying method is relatively simple.

First of all, spread the freshly harvested fruit on the exposure field for a week or two until the fruit crackles and dries naturally. After that, the dried pulp, endocarp and silver peel are removed by a sheller. Coffee beans refined in this way are slightly sour and slightly bitter. Almost all coffee beans produced in Brazil, Ethiopia, Yemen and other places are obtained in this way. The disadvantage of this method is that it is easily affected by weather and is easy to be mixed with defective beans and other impurities. Therefore, it must be carefully screened.

Another way is to wash the fruit, in which the fruit to be harvested is put into a flowing trough. After the floating fruit is removed, the skin and flesh are removed by a pulp remover. Then put it in the sink to remove the emerging pulp. After that, move into the fermentation tank, soak for half a day to a day, and then dissolve the gum on the surface of the fermented coffee beans. After washing with water, drying it for a few days, drying it with a machine, and finally using a sheller to remove the endocarp to become a commercial raw coffee bean.

Water-washed coffee beans have more beautiful color and less impurities. Colombia, Mexico, Guatemala and other countries adopt this method for about 70% of their output. Sometimes in the fermentation process, if not handled properly, it may give off fermentation odor and its unique sour taste, but if handled properly, all kinds of beans can give off their unique coffee aroma. In order to be delivered completely to the destination, raw coffee beans are packed in sacks and placed in special containers for long-distance merchant shipping trips.