What Are the Methods of Honey Processing Coffee Beans? The Drying Process of Honey Process Coffee?

Coffee Bean Honey Processing Methods: Types, Drying Process, and Brewing Recommendations

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Understanding Coffee Cherry Structure

When coffee cherries mature, they turn bright red. Due to their cherry-like shape, they are called "coffee cherries." Before discussing various green bean processing methods, let's first understand the structure of coffee fruit. From outside to inside, they are: fruit skin → pulp → mucilage layer → parchment layer (seed coat) → silver skin → seed.

The mucilage layer is about 1-2mm thick and can be imagined as the translucent substance around tomato seeds, making it difficult to remove. The green beans we typically purchase are actually the innermost seeds (which contain some residual silver skin). Regardless of the processing method used, the goal remains the same—to remove the skin and extract the beans. Different processing methods are employed based on economic cost considerations and natural environmental conditions such as climate. What kind of flavors do different processing methods produce?

Currently, the main processing methods are: natural processing, washed processing, and honey processing.

Natural processing involves directly exposing coffee cherries to sunlight before removing the outer shell and mucilage layer. Washed processing removes the coffee pulp before sun exposure and uses fermentation to eliminate the mucilage layer. Honey processing falls between natural and washed methods, removing the coffee pulp while preserving the mucilage layer for direct sun exposure.

🔆 Natural Processing Method

Natural processing is the oldest, most primitive, and most straightforward green bean processing method. Harvested coffee cherries are spread out to receive direct sunlight exposure, reducing moisture content from 60% to about 12%.

Step 1: Remove Floating Beans

The harvested coffee fruits are poured into large water tanks. Mature, full fruits sink to the bottom, while underdeveloped or overripe fruits float to the surface. First, remove the floating beans.

Step 2: Natural Sun Drying

Next, the entire coffee fruit with pulp and skin is placed on drying patios for sun exposure, requiring several turns daily. This process typically lasts about 2-3 weeks, depending on local climate. When the internal moisture content of coffee beans drops to 10-14%, the sun drying step is complete.

Step 3: Hulling

The naturally dried fruit is processed through hulling machines to remove the hard dried fruit skin, pulp, and parchment layer, extracting the desired green beans.

Advantages of Natural Processing:

1. Simplicity and low cost (except for the floating bean removal step, no water is needed, and one bucket of water can be reused multiple times, making it cost-effective. Therefore, it's widely used in areas with limited water resources and less affluent regions)
2. Enhanced fruit flavors as green beans naturally dry within the pulp, absorbing fruit essence, resulting in richer fruit aromas, noticeable sweetness, and superior body

Disadvantages of Natural Processing:

1. Inconsistent quality in some producing regions where floating bean removal is not performed during natural processing
2. During drying, pulp can easily mold due to climate moisture reabsorption, contaminating the green beans
3. Machine hulling can easily damage green beans, causing appearance defects

Due to the shortcomings of traditional natural processing, the washed method was developed.

💧 Washed Processing Method

Washed processing is currently the most common green bean processing method. Harvested berries are processed through depulpers to separate most of the pulp from the coffee beans. The parchment coffee is then guided to clean water tanks and soaked for fermentation to completely remove residual pulp layers. Through water processing, immature and defective beans are selected out due to buoyancy differences, and the fermentation process is better controlled. Therefore, unlike natural processed beans which may have impurities, washed beans present distinct fruit acidity, slightly stronger complexity, and cleaner profiles. However, because they are too "clean," the richness of flavors is somewhat weaker.

Step 1: Remove Floating Beans (same as natural method)

Step 2: Pulp Removal

Fresh coffee cherries are sent through pulping machines to remove the fruit skin and pulp. Immature fruits, due to difficulty in pulp separation, are eliminated at this stage. After pulping, what remains are mucilage, parchment, and seeds.

Step 3: Fermentation to Remove Mucilage

The seeds with mucilage are moved to fermentation tanks. Although called "washed processing," it doesn't actually wash away the mucilage but uses fermentation to biologically decompose it. The fermentation process takes about 16-36 hours, during which frequent stirring is required to accelerate mucilage separation from the seeds. Washed fermentation produces acidic substances like citric acid, malic acid, and acetic acid. These acids penetrate the green beans, making washed coffee more acidic than natural processed coffee. After fermentation completion, true washing occurs—thoroughly cleaning the beans again.

Step 4: Drying

After washing, the beans still need sun or machine drying to reduce moisture content to 10-14%. Since the pulp has been removed in washed processing, there's no need to worry about mold issues during drying like in natural processing. The dried parchment coffee beans are not as hard as natural processed beans containing pulp and fruit skin, and can be hulled using hulling machines to obtain green beans.

Advantages of Washed Processing:

1. Green beans have deep green color, complete appearance, and excellent marketability
2. Since pulp is removed initially, there's less concern about mold issues
3. Higher acidity and brightness than natural processed beans, with cleaner flavor profiles

Disadvantages of Washed Processing:

1. Complex and tedious process, making it much more expensive than natural processing
2. Requires large amounts of fresh water—producing 1kg of coffee beans consumes 40-50 liters of fresh water, making it less used in water-scarce regions

💦 Semi-Washed Processing Method

An improved processing method developed to reduce water consumption of traditional washed processing.

Step 1: Remove Floating Beans (same as washed method)

Step 2: Pulp Removal (same as washed method)

Step 3: Mechanical Mucilage Removal

Instead of using fermentation to remove mucilage as in traditional washed processing, this improved method uses mucilage removers to mechanically eliminate mucilage.

Step 4: Drying

Sun or mechanical drying to 10-14% moisture content. Semi-washed coffee flavors fall between natural and washed coffees—less acidic than washed but not as sweet as natural processed coffee.

🌰 Honey Processing Method

Honey processing doesn't mean coating coffee beans with honey! The "honey" here refers to the mucilage layer of the coffee pulp. After harvest, coffee cherries are processed through depulpers to remove the outer fruit skin, leaving the pulp to be sun-dried, allowing the pulp's sweetness to penetrate the beans without requiring as much time as natural processing. This is currently a popular processing method.

Honey processing is complex and very labor-intensive. If not properly controlled, the entire batch of beans can have over-fermented rotten flavors. However, when done well, the sweetness of coffee beans is relatively high. The advantage of honey processing is reducing bean acidity while providing more refined aromas. However, this is the flavor achieved when honey processing is perfectly executed. When poorly executed, the coffee tastes unpleasantly acidic like vinegar, with spicy aromas resembling onion or garlic. Even when executed quite well, it still carries some earthy notes, less clean aftertaste, and more impurities than typical washed processing. Therefore, overall, honey processing carries much higher risks than general wet processing methods.

Challenges of Honey Processing:

1. During the drying process, since the viscous pulp layer remains on the coffee beans, frequent turning is required during the initial days to prevent beans from clumping together, requiring more labor than typical washed processing
2. If not dried quickly, beans easily over-ferment
3. If turning is insufficient, the overall environment is too humid or cold, or if the viscous pulp layer is left too thick, coffee beans easily mold. Therefore, some coffee estates use machines to control the thickness of the remaining viscous pulp layer, allowing beans to dry faster and achieve better overall flavor consistency
4. Compared to wet processing, it requires more space and longer drying time

Differences Between White, Yellow, Red, and Black Honey Processing

Coffee farmers classify coffee, with some retaining less mucilage layer for faster drying, while others retain more mucilage layer requiring longer drying time.

• White Honey (retaining approximately 5-10%) - only keeps a small amount of mucilage layer
• Yellow Honey (retaining approximately 25-30% mucilage layer) - for faster completion, must be done in minimal shade environment, resulting in yellow appearance. Yellow honey processed green beans have the longest sun exposure time. Longer sun exposure means higher heat, so this coffee can be dried within 1 week
• Red Honey (retaining approximately 50-75% mucilage layer) - green bean drying time is 2-3 weeks, requiring some shade for sun exposure to reduce sunlight time
• Black Honey (retaining approximately 100% mucilage layer) - drying is usually covered to extend drying time. Black honey processing is the most complex (due to extended drying time requiring longer monitoring to prevent mold and fermentation), with highest labor costs, making it more expensive

In terms of flavor, yellow honey has a clean and bright profile similar to washed processing, while black honey approaches natural processing with rich fruit aromas and full body. Red honey falls in between.

Suitable Coffee Beans

Costa Rican coffee is the most stable quality among Central American coffees, mainly because coffee grows in the natural environment of complete large tree shade, cool rainy nights, and significant temperature differences between morning and evening. Combined with fertile soil and stable, progressive post-processing, Costa Rican coffee maintains its reputation, long serving as the benchmark for Central American coffee.

Wet processing emphasizes clean, clear mouthfeel with acidity that flashes like a razor, while honey processing emphasizes complex, layered mouthfeel with reduced acidity and increased sweetness. Washed beans have always been Costa Rica's most important coffee processing method. Some coffee enthusiasts love the sweet sensation and delicate toffee-like aftertaste of honey processing, but washed Costa Rican beans, while lacking the appealing sweetness, maintain the good impression of high-quality coffee in the mainstream where sweetness reigns, with their clean, bright, and high mouthfeel and consistently delicate, vibrant acidity.

Sharp, bright, and thin citrus acidity has long been the world's impression of Costa Rican washed beans, but Rose Estate somewhat deviates from this impression, attracting our attention with pure, refreshing, impurity-free high mountain tea aromas. We don't recommend heavy roasting (starting second crack) because the aromatic, rich chocolate and nut notes can be obtained in honey-processed Costa Rican coffee.

FrontStreet Coffee's Pour-over Reference:

Using a V60 dripper, 15g of coffee grounds with 32g of water, bloom for 30 seconds. Extract with 89-90°C water at 1:15 ratio, medium-fine grind (Fuji R grinder 3.5). Second pour to 110ml, wait for water to drop, then slowly pour water with even speed, keeping water level not too high. Pour again to 233ml and stop. Extraction time 2:15 seconds—rich natural sweetness. Everyone can fine-tune according to their taste preferences.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473