Kopi Luwak | Civet Cat Digestive Fermentation Principle? Sidamo Guji Premium Natural Fermentation Processing Method?

Civet Coffee | Fermentation Principles in the Civet Cat's Body? Sidamo Ardi Natural Process Fermentation?

Natural Process: Creating Intense Wine Aromas

The natural process is the most primitive, simple and time-honored coffee processing method. According to relevant literature, as early as over 1000 years ago in the 11th century, Arabs were already using the natural process to handle coffee fruit.

Processing Steps:

First, coffee fruit is poured into large water tanks, where underdeveloped, inferior beans float to the surface. The mature, full fruits that sink to the bottom are scooped up, spread evenly for sun exposure, frequently turned, and any defects are sorted out.

When the moisture content inside the beans drops to 10%-14%, a hulling machine is used to remove the skin and pulp, completing the entire natural process.

Disadvantages:

The natural process depends entirely on the weather, making the dryness of the fruit difficult to control. If the drying area is not clean, impurities easily mix in. Because the pulp is not removed during natural drying, mold and rot often occur. Many people therefore view naturally processed beans as having poor quality control and unlikely to achieve high grades.

Advantages:

Apart from the first step of filtering out inferior beans with water, the natural process requires no water in its other steps, and the water can be reused repeatedly. In regions with limited water resources, this method is simply excellent. And because natural beans carry irreplaceable special flavors, some outstanding estates have begun treating natural beans seriously, placing them on racks to prevent contamination and selecting carefully, which is why we now see so many high-quality natural coffees.

Flavor:

Although natural beans have an uneven appearance and marked color differences, because the beans mature naturally inside the fruit without interference from the external environment, naturally processed coffee has more intense flavors, with wine-like fermentation notes and sweetness.

Washed Process: Creating Clean Acidity

Because of the shortcomings of the natural process, the Dutch invented the washed process in the mid-18th century, and it gained widespread popularity. Its biggest difference from the natural process is that it uses fermentation to remove the outer skin.

Processing Steps:

As in the first step of the natural process, inferior beans are removed first, then a pulping machine removes the skin and pulp, and the fruit is thrown into water tanks for 16-36 hours of fermentation. Fermentation bacteria dissolve the mucilage.

To remove residual fermentation bacteria and impurities, the beans are cleaned again, then machines dry the fruit until moisture content drops to 10%-14%. Finally a hulling machine removes the silver skin around the beans to complete the process.

Disadvantages:

As the name implies, the washed process mostly requires water, so in countries lacking water resources it cannot be widely adopted. It is also relatively cumbersome and much more expensive than the natural process.

Advantages:

It goes through multiple layers of screening and cleaning, resulting in a cleaner, more uniform appearance and taste. And because the pulp is removed at the beginning, there is no need to worry about mold as there is with the natural process.

Flavor:

Washed beans typically have bright, clean acidity, because acidic substances develop during fermentation in the tanks.

Semi-Washed Process: Removing Both Skin and Mucilage

Because the washed process uses too much water, the semi-washed process emerged. It is a hybrid of the natural and washed processes, a compromise between the two.

Processing Steps:

First, as in the two methods above, inferior beans are removed. Then the fruit is poured into a pulping machine to remove the skin and pulp.

To reduce water consumption, the semi-washed process uses a demucilager to remove mucilage, then dries the fruit with machines or in the sun outdoors.

When the moisture content of the fruit drops to 10%-14%, a hulling machine removes the silver skin sticking to the beans, completing the process.

Disadvantages:

Although it is a hybrid of the washed and natural processes, its procedure is as cumbersome as the washed process.

Advantages:

It has the cleanliness of the washed process without requiring large amounts of water.

Flavor:

The semi-washed process has the fewest variables affecting quality. Its acidity is slightly lower than washed beans but higher than natural beans; its sweetness is lower than honey-processed beans, but its cleanliness is better than honey processing, placing its flavor between honey and washed.

Honey Process: Extracting Sugar from Mucilage

The honey process (called Miel Process in Spanish) is also known as the semi-natural process. It is the most trendy and distinctive processing method of recent years. Its main difference from the natural process lies in whether pulp removal happens before or after sun-drying.

Processing Steps:

Again, the first step is removing inferior beans, then a pulping machine removes skin and pulp, followed by sun-drying to reduce the moisture content of the fruit to 10%-14%. Finally a hulling machine removes the silver skin sticking to the beans to complete the process.

Disadvantages:

Among mainstream coffee processing methods, it is considered the most complex and demanding.

Advantages:

It is an improved version of the natural process, effectively solving the mold problem in the beans while reducing water costs.

Flavor:

Because it is sun-dried with the mucilage still on, the sugar in the mucilage enters the beans during drying, resulting in balanced sweet-and-sour flavors with a rich body. In recent years many competition-winning beans have come from honey processing, with Costa Rica's honey processing particularly famous.

Fermentation Process (Civet Cat Internal Fermentation)

Animal Internal Fermentation: Creating Gentle, Mellow Aromas

As for animal internal fermentation, the author personally finds it extremely cruel, the most typical example being civet cat coffee (kopi luwak).

Principles:

It uses lactic acid bacteria and digestive fluids from the animal's digestive tract to remove the pulp and mucilage attached to the bean surface. The beans are excreted with the feces and, after cleaning, become precious internal fermentation beans. Besides civet cats, animal internal fermentation beans include those from guans, monkeys and elephants, but the latter few have not formed large-scale operations, with only the civet cat standing out.

Initially this was because civet cats come out at night and rely on sight and smell to pick specifically the reddest coffee fruits, showing no interest in half-ripe green fruit, so the excreted beans are all perfectly ripe specialty beans. After these feces-borne beans are cleaned and roasted, all bacteria are killed. Their greatest characteristic is a gentle flavor with an enhanced mouthfeel, while the fundamental flavor depends on the coffee varieties the civet cat has eaten.

In New York a pound of civet cat coffee costs five hundred dollars, while in Hong Kong a cup costs fifty dollars. Later, people spotted the business opportunity and began large-scale civet cat farming, constantly feeding the animals coffee beans to produce more kopi luwak for profit.

In reality, different production regions adapt to local conditions and adopt the processing method best suited to them. When a coffee bean reaches your cup, farmers must weigh not only cost but also which processing method best suits that fruit, so its flavor comes through more prominently and deliciously.

FrontStreet Coffee Recommended Brewing [V60 Pour-Over]:

Dripper: Hario V60

Water Temperature: 88°C

Grind Size: Fuji Royal grind level 4

Brewing Method: Water-to-coffee ratio 1:15, 15g of grounds. First pour 25g of water for a 25s bloom. Second pour to 120g and stop. Wait until the water level in the coffee bed drops to half before continuing to pour. Pour slowly until reaching 225g total water. Extraction time around 2:00.

Analysis: Three-stage brewing clearly separates the front, middle and back-end flavors of the coffee. Because the V60 has many ribs and drains quickly, stopping the pour extends extraction time, better drawing out the nutty and chocolate flavors from the back end.

FrontStreet Coffee Recommendation

Processing method shapes the cup, and Ethiopia is the best place to taste that difference for yourself. FrontStreet's Washed Yirgacheffe is the classic clean profile: washed processing strips the pulp and develops bright acidity, giving clear jasmine florals and a lively citrus acidity over a light, elegant, tea-like body, like a clean glass of lemon tea. If you want to compare with the natural side, FrontStreet's Yirgacheffe Red Cherry is a whole-cherry natural that keeps the classic Yirgacheffe character while adding tropical fruit, berry juice, honeyed sweetness and creamy smoothness. FrontStreet's Kafa Forest represents the wild end of the spectrum: unlike the garden-style plots where many farmers grow coffee behind their homes, Kafa is known for wild coffee, with trees growing between 1,400 and 2,100 meters under shade, in a pristine microclimate with red soil and abundant rainfall. Roasted medium-light, it grinds with clear white florals and enters with bright lemon acidity, sweet orange and bergamot, a faint melon and nut sweetness in the finish, and a green-tea-like body.