Barista's basic knowledge of Learning and training (2)

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The basic knowledge of becoming an excellent barista is very important. This article is written by Xi'an Aike Coffee training Institute based on years of teaching, followed by a complete collection of basic knowledge of baristas' learning and training.

Coffee bean picking

Most of the coffee harvesting in the world is selected by hand, so it is a labor-intensive and seasonally intensive process. Since there are both flowers and fruits on the same branch, the index finger and thumb of the collector are the best tools for collecting ripe berries. Scraping the fruit off a whole branch by hand or using an automated harvester can't tell ripe berries from green berries.

Coffee farmers who produce low-grade coffee beans like to use labor-saving methods to harvest beans, but in this way, because the quality is not pure, it impairs the flavor of coffee and lowers the grade of coffee. The way to pick coffee beans in some parts of Africa is to shake coffee trees, shake the fruit off the ground, and pick it up from the ground before the fruit is injured and rotten. Secondary coffee is produced in most parts of Brazil, where coffee is picked by plucking all the leaves, flowers, overheated and green fruits from the branches at a time, and it takes two years for such damaged coffee trees to return to normal.

Coffee cherry

1. Skin/Pulp: the outermost layer of coffee beans is covered with berry-like skin and pulp. In addition to the natural sun method, coffee beans treated by other methods must remove the skin and flesh within a few hours after picking. For coffee, peel and pulp are important by-products. In some places, people use the peel and pulp of coffee to make tea. People in the industry are accustomed to calling the skin and pulp of coffee "Pulp", while the machine used to remove the pulp is called "desizing machine".

two。 Mucous membrane (Mucilage): under the skin and pulp, a thick layer of mucus tightly wraps the coffee beans. Because this mucous membrane is extremely sticky and high in sugar, it is used to call it "Honey". Not only coffee, but also many fruits have a layer of mucus inside.

3. Parchment (Parchment): inside the mucous membrane, a thin film of cellulose surrounds the coffee beans. After drying, the film looks like parchment, hence the name.

4. SilverSkin/Chaff: there is a thinner film inside the parchment that wraps the coffee beans. Because the color is glossy and silvery, people used to call it "silver skin". This layer of silver will fall off during baking. Usually when you grind the coffee, you find some silver crumbs in the coffee powder. These crumbs are the silver skins that fail to peel off the coffee beans during baking.

5. Coffee beans: each fruit contains 2 coffee beans (except for a single pod bean Peaberry. The fruit of this kind of coffee contains only one coffee bean. Normally, 5% of each batch of coffee beans is a single pod. Coffee beans can be roasted after drying and processing.

Treatment methods of raw coffee beans

[sun exposure]

Show a strong aroma of wine

This is the most primitive, simplest and oldest way to treat coffee.

First pour the coffee beans into a large tank, and the poorly developed beans will float on the surface and pick up the ripe and full fruits that sink to the bottom of the water.

The tile is exposed to the sun, often flipped over, picking out defects.

When the water content in the coffee beans is reduced to 10%-14%, the peel pectin can be knocked off with a sheller, and the whole solarization method is complete.

Disadvantages:

The sun method depends entirely on the weather, and the dryness of coffee fruit is difficult to control. The sun field is not clean and it is easy to mix with impurities. In the process of the sun, the pulp of the coffee fruit has not been removed, so it is often moldy and rotten. Therefore, in the view of many people, the quality of sun-exposed coffee beans is not controllable and the level is not too high.

Advantages:

Except for the first step of using water to filter out inferior beans, the other steps do not need any water, and can be used repeatedly in areas where water resources are not abundant.

And because sun-dried beans have irreplaceable special flavor, some excellent farms begin to take sun-dried beans seriously, such as putting them on shelves to prevent pollution and fine selection, so today we can see a lot of high-quality sun-dried coffee beans.

Flavor:

Although the sun-cured beans are uneven in appearance and different in color, because the coffee beans ripen naturally inside the fruit and are not disturbed by the external environment, the sun-cured coffee beans have a stronger flavor, wine-like fermented taste and sweet taste.

[washing method]

Wash out a clean sour smell

Because of the shortcomings of the solarization method, the Dutch invented the washing method in the mid-18th century, which was widely favored. The biggest difference from the sun method is that it uses fermentation to remove the skin.

The process is the same as the first step of the solarization method, the first step is to remove the inferior beans.

Then use pulping machine (pulp planer) to remove the peel and pulp of the coffee fruit.

Throw it into the sink to ferment for 16-36 hours, and the fermentative bacteria dissolve the pectin.

In order to remove the residue of fermentation bacteria and impurities, the coffee beans will be washed again.

The coffee fruit is then dried by machine so that the moisture content is reduced to 10% Murray 14%. Finally, the use of shelling machine to remove the silver skin on the coffee beans can be completed.

Disadvantages:

Water washing, as its name implies, mostly requires water, but it is unlikely to be adopted in some countries that lack water resources. The process of washing is also relatively cumbersome and the cost is much higher than that of tanning.

Advantages:

After layers of screening and cleaning, the appearance and taste will be cleaner and more uniform. And because the flesh is removed in the first place, you don't have to worry about mildew as much as the sun.

Flavor

Washed beans usually have bright and clean acidity because they ferment acid in the fermentation tank.

[semi-washed]

It is a mixture of sun exposure and water washing, and it is also a compromise between the two.

First of all, the treatment process is the same as the above two treatments, first removing inferior beans.

Then pour the coffee fruit into the pulp planer to remove the peel and pulp.

In order to reduce water consumption, the semi-washing method uses a pectin scraper to remove pectin.

Finally, the coffee fruit is dried or exposed outdoors.

Reduce the water content of the coffee fruit to 10% Murray 14%, and then use the sheller to remove the silver skin from the coffee beans.

Disadvantages:

Although it is a mixture of washing and tanning, its process is as tedious as washing.

Advantages:

With the cleanliness of the washing method, it does not need to consume a lot of water.

Flavor:

The semi-washing method had the least influence on the quality, and the sour taste of coffee was lower than that of washed beans and higher than that of sun-washed beans; the sweet taste was lower than that of honey treatment, but the cleanliness was better than that of honey treatment, and the flavor was between honey treatment and water washing.

[honey treatment]

Honey treatment (Miel Process in Spanish) is also called half-sun treatment. It is the most fashionable and characteristic treatment in recent years, and the main difference between it and the sun method is whether the pulp is removed before or after the sun. And there are many kinds of honey treatment methods-- red honey, black honey and so on.

Treatment process: again, the first step is still to remove shoddy beans.

Then through pulping machine (pulp planer), the peel and pulp are removed.

After the sun exposure, the water content of the coffee fruit was reduced to 10% Murray 14%.

Finally, the sheller is used to remove the silver skin sticking to the coffee beans.

Disadvantages:

Among the several mainstream ways of handling coffee beans, it is the most complex and painstaking.

Advantages:

It belongs to the improved method of tanning, which effectively changes the problem of mildew of coffee beans and reduces the cost of water.

Flavor:

Because it is in the sun with pectin, the sugar in the pectin enters the beans during the drying process, making the coffee beans sour and sweet balanced and mellow. In recent years, the winners of many competitions have come from the honey treatment process, which is quite famous in Costa Rica.

[Indonesian semi-washing]

Also known as wet planing, mainly exists in the Indonesian island of Sumatra. Locally, coffee removes the peel and flesh, removes the gum, and dries the endocarp when it retains the endocarp, but not completely to 10% of the moisture content of 12%, but to remove the endocarp after partial drying. At this time, the water content of raw beans is very high, the volume of coffee is very large, and the color is white. The large raw beans go into drying again, and the color gradually changes to dark blue-green. At this time, the coffee is packed and ready for export. Indonesian semi-washing brings low acidity and boredom, high alcohol thickness, spices and lack of clarity of coffee.

Brazilian peeling and tanning

After removing the peel and pulp, the gum is left on the coffee, completely dried to about 10% of the moisture content, and then bagged to recuperate the coffee, remove the endocarp and prepare for export and sale. Brazilian peel-free sun and honey treatments are usually sour and sweeter, with flavors more inclined to sweet fruits and nut chocolates.

The grading of coffee is determined by the producing countries of coffee beans, and the methods of expression are not the same. It is mainly determined according to the altitude of the place of origin, the size of bean grains and the number of defective beans. Because the grading criteria of many countries of origin are very simple (such as Colombia, which is determined only by the size of beans), and the grading does not need to be tested (Cupping), the grade of coffee beans can only be used as a general reference and can not fully reflect the taste of coffee beans.

The unit used to determine the size of the beans is "Screen size", that is, the number of sieve plates used to screen coffee beans, represented by S + numbers. When the number increases by 1, the diameter of the sieve hole increases by 1 inch. Therefore, "S18 and above" means "cannot pass through a sieve plate with a sieve hole diameter of 18,000,000 inches". In general, the larger the coffee beans, the richer the nutrients absorbed by the fruit and the better the taste.

Defective beans include green beans peeled from unripe berries, stunted "shell beans", black beans caused by mildew or rotten fruit before harvest, moth-eaten beans, broken beans, berries that have not removed their flesh; it also includes pebbles, corn kernels and even bird droppings mixed in the drying process. Is the main source of coffee odor.

The algorithm for all kinds of defective beans is per 300g sample.

Large foreign bodies (pebbles, bird droppings, wood chips, etc.): 5 o'clock each

Medium foreign body: each at 2 o'clock

Small foreign bodies: 1 o'clock each

Black beans, moldy soy milk fruit: 1 o'clock each

Moth-eaten beans: 1 point every 2-5

Shell beans, green beans, chopped beans: 1 point every 5

Brazilian coffee beans in addition to distinguishing "Type" by size and broken bean points

Through the evaluation of the trial drink, a suffix indicating the taste and quality will be added, from high to low:

Soft= tastes pure and soft, with less peculiar smell.

Hard= has a green taste and a bitter taste.

Rio= has the pungent smell of herbs.

The grading of Indonesian coffee is also based on the size of beans and the number of incomplete beans, but it is not comprehensively evaluated. The sieve hole diameter greater than 7.5mm is "Large", and the sieve hole diameter greater than 3mm is "Small". The number of incomplete beans below 11 is G1Magol below 25, G2Magol 44 is below G3pjori80, and below G4150 is G5. Marked as "Large G1" or "Small G3" and so on.

Roasting of coffee beans

Roasting of coffee beans (Rosting): stir-fry raw beans in a bean dryer to add flavor and aroma to coffee, the main purpose is to promote aroma, increase the complexity of coffee, obtain color, form the unique flavor of coffee and so on.

When coffee beans are heated in stages in a bean dryer (usually using large, hot rotating cylinders), the remaining water in the coffee bean cells turns into steam, prompting the rich sugars, proteins, lipids and minerals to undergo a variety of complex chemical reactions. Coffee beans begin the caramelization process between 170C and 200C. At 185240 ℃, sugars combine with amino acids, peptides and proteins for caramelization, which is also known as the Mena reaction.

Several stages of roasting of coffee beans

1. Very shallow baking (LIGHTRoast):

The degree of baking; very shallow baking, also known as shallow baking.

2. Shallow baking (CINNAMONRoast):

Degree of baking; shallow baking, also known as cinnamon baking.

3. Micro baking (MEDIUMRoast):

Baking degree; moderate baking, also known as micro baking.

4. Medium baking (HIGHRoast):

Baking degree; moderate micro-deep baking, also known as concentration baking.

5. Medium and deep baking (CITYRoast):

Baking degree; medium-deep baking, also known as urban baking.

6. Deep baking (FULL-CITYRoast):

Baking degree; micro-depth baking, also known as deep city baking.

7. Very Deep Baking (FrenchRoast):

Degree of baking; deep baking, also known as French baking.

8. Very Deep Baking (ItalianRoast):

Degree of baking; very deep baking, also known as Italian baking.

Boutique coffee

Ms. Knudsen of the United States proposed it in Coffee and Tea magazine. At that time, Ms. Knudsen, as a coffee buyer of B.C. Ireland in San Francisco, ignored the quality of raw coffee beans in the industry, a term used to describe coffee beans growing in a special environment with distinctive flavor characteristics.

At the beginning, people drank fine coffee, but later, due to the growing demand for coffee, the discovery and use of new coffee varieties led to a decline in coffee quality. in this case, Ms. Knudsen re-made people realize the value of fine coffee, thus the rise of boutique coffee craze. The market for boutique coffee is also growing. In the 1990s, with the rapid increase of boutique coffee retailers and cafes, boutique coffee has become one of the fastest growing markets in the catering service industry, reaching $12.5 billion in the United States alone in 2007. Now boutique coffee has become the fastest growing coffee market. Coffee producing and importing countries around the world are aware of the great potential of the boutique coffee market, and continue to make efforts to the production and production of boutique coffee.

The concept of boutique coffee

1. Fine coffee is made from boutique coffee beans.

two。 Boutique coffee is fresh coffee.

3. Boutique coffee is good coffee and is harmless to health.

4. Boutique coffee has a rich and beautiful taste.

Characteristics of boutique coffee beans

1. Boutique coffee beans must be high-quality beans with flawless beans.

two。 Fine coffee beans must be excellent varieties.

3. The growth environment of boutique coffee beans also has higher requirements.

4. The best way to harvest high-quality coffee beans is to harvest them manually.

5. High-quality coffee beans are refined by water treatment.

6. Boutique coffee has a strict grading system.

The judgment standard of fine coffee

American Fine Coffee Association Standard:

1. Whether it has rich dry aroma (Fragrance). The so-called dry aroma refers to the aroma of roasted or ground coffee.

two。 Whether it has rich wet aroma (Aroma). Wet aroma refers to the aroma of coffee extract.

3. Whether it has rich acidity (Acidity). It refers to the sour taste of coffee, the combination of rich sour taste and sugar can increase the sweet taste of coffee liquid.

4. Whether it has rich alcohol thickness (Body). It refers to the concentration and weight of the coffee liquid.

5. Whether it has rich afterrhyme (Aftertaste). It refers to the afterrhyme of coffee, which is evaluated according to the flavor after drinking or spitting.

6. Whether it has rich taste (Flavor). Refers to the taste, the upper palate to feel the aroma and taste of coffee, to understand the taste of coffee.

7. Whether the taste is balanced or not. Refers to the degree of balance and combination between the various flavors of coffee.

Evaluation criteria for producing countries:

1. A variety of fine coffee. It is better to use Arabica inherent variety Tibica or bourbon variety.

two。 Whether the altitude, topography, climate, soil and refining method of the cultivation land or farm are clear, generally speaking, the coffee with high altitude is of higher quality, and the soil is better with fertile volcanic soil.

3. The harvesting method and refining method are adopted. Generally speaking, it is better to adopt manual harvesting method and water washing refining method.

Single product and Italian combination

Single product

Pure coffee made from a single coffee bean produced in the country of origin and usually drunk without milk or sugar. Have a strong characteristic

Single coffee extraction tools and usage: siphon kettle, filter paper dripping (also known as hand flushing), steam pressurized kettle, curling kettle

, American filter drip pot, French filter kettle

Matching

Blended coffee is the blending of two kinds of high-quality coffee will suppress each other's unique flavor, blending should also pay attention to color, the matching coffee beans also have different characteristics to reconcile the attractive taste, used in the production of Italian coffee.