Coffee Newbie Class丨How Much Do You Know About Coffee Beans?

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The History of Coffee Beans

First, let me tell you the history of coffee beans.

Legend has it that around the 10th century AD, on the plateau of Ethiopia in Africa, a shepherd named Carl discovered that his sheep became very excited after eating a certain red fruit. So Carl distributed this incredible red fruit to the locals, and its magical effect spread.

Photo: Red berries on a coffee tree

There is another legend that in 1258 AD, in the mountains of Yemen, Sheik Omar, a chief who was expelled by his tribe for committing a crime, was exiled to Wasaba (in Arabia). When he was walking exhausted on the mountain, he found that the birds on the branches made very pleasant and melodious chirping sounds after pecking at the fruits on the trees. So he boiled the fruits with water and drank it. After drinking it, the original feeling of fatigue was also eliminated.

Later, Omar collected a lot of these magical fruits. When he met someone who was sick, he made a soup with the fruits for them to drink, which restored their spirits. Because he did good deeds everywhere, his sins were soon forgiven. When he returned to Mocha, he was revered as a saint for discovering this fruit. It is said that the magical medicine for curing diseases at that time was coffee.

However, the real documented spread of coffee beans originated from Africa. The specific process is shown below:

Reference indicators for coffee bean grading

In fact, there is no unified classification system in the coffee industry. Each producing country has its own classification system. For example, Brazil sets NO.2 as the highest grade, while Jamaica sets NO.1 as the highest grade.

Personally, because people have different preferences and tastes, the grading cannot fully present the flavor of coffee, it is more about the quality of coffee, so the coffee grade is not very important to me. I think you can only know the good coffee after tasting it. Moreover, domestic coffee stores usually do not mark the grade. You can only see Colombian coffee, Mandheling coffee, Kenyan coffee, etc., but you can't see the grade. So, taste is the hard truth.

However, in general, the following three indicators can be used for classification:

(1) Size of coffee beans

Some people say that the size of the beans does not affect the flavor of coffee. For example, the Mattari coffee from Yemen has beans of different sizes, but it is still a top-grade coffee. However, in many production areas, the size of coffee beans is indeed a very valuable reference indicator.

The regions that generally use this classification method include Kenya, New Guinea, Puerto Rico, Zimbabwe, Tanzania and Uganda. In addition, many Brazilian coffees also use this classification method.

(2) Points for defective beans

This is the earliest grading method, and it is still used in many areas of Brazil. The identification method is to randomly select a 300-gram sample, find the defective beans in the sample, and accumulate different scores according to the type of defect. After the identification is completed, the grade is rated Gr2~Gr8 according to the accumulated defect score, but there is no Gr1. If you want to buy the first-grade Brazilian beans, you will make a fool of yourself.

Picture: Defective coffee beans

Indonesian and Ethiopian coffee beans are also graded in this way. Indonesian beans are mainly graded into 6 grades: Gr1~Gr6. Ethiopian beans are divided into 5 grades, of which Gr1~Gr2 are reserved for washed beans. Washed beans Gr1 means that there are only 0~3 defective beans per 300 grams of raw beans, while Gr2 means that there are 4~12 defective beans per 300 grams; the quality of sun-dried beans is Gr3, Gr4 or Gr5.

(3) Origin of coffee beans

Coffee beans are processed from the fruits of coffee trees. Coffee trees grow between 25 degrees north and south latitude, centered on the equator (as shown in the figure below), that is, in tropical and subtropical regions.

There are currently more than 60 coffee producing countries, and its production areas are distributed in South America, Central America, the West Indies, Asia, Africa, Arabia, the South Pacific and Oceania.

Figure: Coffee producing countries around the world

The best coffee beans in the world are produced in Indonesia and Colombia. In terms of production, Brazil ranks first in the world, accounting for about 30%, followed by Central and South America centered on Colombia, followed by Africa and Arabia, and the remaining 10% is distributed in Asia and various islands.

In addition, Central American countries such as Guatemala, Costa Rica and El Salvador are all located in mountainous areas. The farms in the country are located in mountainous areas of different heights, so the quality of coffee can also be distinguished by the altitude of the origin.

(4) The age of coffee beans

New coffee is called "new beans", which refers to the coffee beans harvested in the current year. The coffee beans produced in the previous year are called "old beans". The beans harvested a few years earlier are called "old beans". Only the new beans produced in the current year are high-quality products, because the taste and aroma of new beans are stronger.

Figure: Comparison of new and old coffee beans

How green coffee beans are processed

After the coffee cherries are picked, the coffee beans must be separated from the coffee cherries as quickly as possible. There are generally several ways to handle them:

The washed method is to pick the coffee berries as soon as they turn red, remove the hard skin with a machine, expose the sticky berries, and then throw them into the pool for fermentation. In about one or two days, bacteria will eat most of the pulp attached to the seeds. The entire fermentation process must be monitored by a master. Too much or too little will damage the quality of the coffee beans. After the fermentation and removal of the berries are completed, the remaining pulp attached to the seeds is washed with clean water.

Next is the drying process. It is best to lay it on the ground and let it dry in the sun for a better flavor. However, if it rains, you can also use a machine to dry it. The temperature must be well controlled. After drying, polish it.

Image: Blue-green washed coffee beans

Generally speaking, washed beans are bluish green, beautiful in appearance, and have a clear and bright fruity taste. Coffee beans from Guatemala, Colombia, Blue Mountain, Kona, Kenya, Java, and Panama are all washed beans. All Latin American countries except Brazil use the washed method.

This processing requires more capital and energy investment and is costly, but it helps to ensure the quality of coffee beans and reduce losses.

There is also a semi-washed method. The first step is the same as the washed method. The fruit is picked when it turns red, but it is not thrown into the fermentation tank. Instead, the peel is removed by machine, and then the berries are spread on the ground to dry. After drying, they are moistened and the dry pulp is ground off with a special machine to remove the seeds. Most of the Mandheling in Indonesia uses the semi-washed method. Brazil has also used the semi-washed method in recent years. It is the only country in the world that combines the three processing methods of sun drying, washing and semi-washing.

Photo: Semi-washed coffee beans

The sun-dried method is to take the red beans and directly dry them in the sun, then forcibly peel and shell them. The beans produced by this method often have defects and are not beautiful. Foreign objects or stones are often found in sun-dried beans. The beans processed by this method have a more complex flavor, with the taste of the sun and a strong fruity aroma. The consistency is better than that of the washed method, but the bean appearance is not good. General Brazilian beans, Mandheling and Mocha are typical sun-dried beans.

Photo: Sun-dried coffee beans

Coffee bean roasting and blending

When you have good quality green coffee beans, the most important steps to make it into high-quality coffee are roasting and blending.

Generally, raw beans have a pungent earthy smell, but after being properly roasted, they will emit a strong aroma. In fact, raw beans contain seven or eight hundred aromatic components, which must be "awakened" by roasting.

First, after the beans are roasted at over 200°C, the moisture begins to evaporate, the volume expands by more than 50%, and the weight decreases by 10%-25% depending on the degree of roasting. The deeper the roasting, the greater the weight loss.

In addition, the green beans release carbon dioxide during the roasting process, and will continue to release gas within 30 days after roasting. Interestingly, this exhaust helps keep the coffee beans fresh, because oxygen molecules are not easy to invade during this process, and the oxidation that destroys the flavor of the coffee cannot be carried out. Then, after 7 days of roasting, the exhaust phenomenon gradually slows down, and oxygen molecules can easily attach to the surface of the beans, and the flavor of the coffee is easy to decline. This is an important reason why coffee beans are best used up within a week after opening.

Professional coffee is generally roasted in small batches. The most common methods are: drum roasting and hot air roasting.

Drum roasters roast coffee beans in rotating drums using gas or wood. When the desired roast degree is reached, the beans are poured into a cooling hopper to prevent over-roasting.

Figure: Drum baking method

Hot air roasters, also called fluidized air roasters, roast coffee beans by tumbling them in hot air. Most green coffee beans are roasted at temperatures of nearly 400 degrees.

Roasting degree is roughly divided into light roasting, medium roasting and dark roasting, but there is no unified standard in the coffee industry. The American roasting degree classification is most commonly used in the industry, as shown in the following table:

Figure: American roasting degree of coffee beans

There are more than 100 coffee producing regions in the world, each producing its own unique coffee beans. The purpose of blending coffee beans is to balance the flavors of the coffee to create an unparalleled taste.

Single coffee beans generally lack the complex flavor necessary to brew a delicious cup of coffee. Many blended coffees contain 3 to 7 different types of coffee beans. For example, in Italy, some Robusta coffee beans are added to blended coffee to increase its oil, caffeine and the complexity of coffee flavor.

A roasting expert understands the characteristics of each coffee bean and blends them artistically to create a desired new flavor. The knowledge of how roasting experts blend coffee beans is considered the most confidential industry secret.

But whether to roast or blend first has always been a controversial issue among roasters. Generally speaking, roasting each single product first and then blending them will maximize the different flavor characteristics of each coffee, thus producing the best effect. The Blaser classic coffee beans launched by Swiss Coffee People adopt this method to bring everyone the most delicious coffee enjoyment.

Figure: Swiss Blaser classic coffee beans

Author: Belly

A homebody, a senior homebody, who likes to hoard all kinds of food. She loves all kinds of drinks, especially coffee. She is a coffee addict and likes to collect all kinds of coffee.

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