Coffee Bean Production Process and Common Coffee Processing Methods

Coffee Bean Processing Methods

Coffee bean processing mainly refers to two things:

1. The method of turning a coffee cherry into a green coffee bean — what we commonly call washed processing, natural processing, and so on.

2. The method of turning a green coffee bean into a roasted bean.

Coffee Processing Methods

The process of transforming coffee cherries into coffee beans is called coffee processing. The number of processing methods keeps growing, but the beans at FrontStreet Coffee basically cover every current mainstream method. The store also displays beans with different processing methods for customers' reference. Today, let FrontStreet Coffee start by introducing the four most basic methods: natural, washed, semi-washed, and honey processing.

Coffee Cherry Structure

A coffee cherry, which resembles a cherry, is made up of the following layers from outside to inside: skin, pulp, mucilage layer, parchment layer (seed coat), silver skin, and seed. The mucilage layer is about 1-2mm thick; imagine the translucent substance around tomato seeds, and you will understand how difficult it is to remove. The green beans we generally buy are actually the innermost seeds, perhaps still carrying some residual silver skin.

Processing Methods Overview

All processing methods share the same goal: removing the skin to obtain the beans. Based on economic cost and differences in natural conditions like climate, the extraction process may not be identical — but the process does affect the result.

Natural Processing Method

Advantages of Natural Processing

1. Simple, with low processing costs.

2. The green beans dry naturally inside the fruit pulp, absorbing the fruit's essence, which yields rich fruit aroma, noticeable sweetness, and excellent body.

Disadvantages of Natural Processing

1. In some producing regions, natural processing does not screen out floaters, causing quality inconsistencies.

2. During drying, the pulp can easily become moldy due to climate-related moisture reabsorption, contaminating the green beans.

3. Machine hulling inevitably damages some green beans, causing appearance defects.

Natural Processing Steps:

Natural processing is the oldest and most hassle-free green bean processing method.

Step 1: Screening Floaters
Place harvested coffee cherries into large water tanks. Mature, full cherries sink to the bottom, while underdeveloped or overripe cherries float to the surface. These floaters must be removed.

Step 2: Natural Sun Drying
Next, place whole coffee cherries with skin, pulp, and parchment intact onto drying patios for natural sun drying until moisture content reaches about 12%. This takes about two to four weeks, depending on the origin's climate.

Step 3: Hulling
Use hulling machines to remove the dried hard skin, pulp, and parchment layer from the naturally dried fruit, revealing the green beans.

Washed Processing Method

Washed processing is currently the more common green bean processing method.

Step 1: Screening Floaters (same as natural processing)

Step 2: Pulp Removal
Send fresh cherries through a pulping machine to remove the skin and pulp. Immature cherries, whose pulp does not separate easily, are screened out at this stage. After the pulping machine, what remains is mucilage, parchment, and seeds.

Step 3: Fermentation to Remove Mucilage
Move the depulped seeds with mucilage into fermentation tanks. Although it is called the "washed" method, it does not actually wash the mucilage away. Instead, fermentation uses biological decomposition to remove it. Fermentation takes about 16-36 hours, during which the beans must be stirred frequently 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 beans more acidic than naturally processed ones. After fermentation, the actual washing begins — washing the beans again.

Step 4: Drying
After washing, the beans still need to be sun-dried or machine-dried to reduce moisture content to 12%. Because washed processing has already removed the pulp, there is no need to worry about mold during drying as with natural processing. The dried parchment beans are not as hard as those containing pulp and skin in natural processing, so they can be hulled to obtain green beans.

Coffee Roasting Process

Roasting Process Description:

1. Bean Selection Before Roasting: Although beans are selected multiple times at origin, FrontStreet Coffee selects them again both before and after roasting.

2. Roasting: Roast according to the bean's roasting profile at 190-202°C for 9-15 minutes.

3. Post-Roasting Bean Selection: Select beans again after roasting.

4. Packaging: Wait for the beans to cool completely, then package and ship by category.

FrontStreet Coffee Recommendation

If the honey-process methods in this guide caught your attention, FrontStreet Coffee has several beans that show the full range. The Cerrado from Brazil is a classic semi-washed (pulped natural) coffee, with clear cream, peanut, nut, and chocolate flavors — semi-washing is the direct ancestor of honey processing. The Costa Rica Blackberry takes the opposite extreme: a black honey process that keeps almost all the mucilage and dries for at least two weeks under cover to slow the moisture loss and fully convert sugars, then is medium-light roasted to release intense floral aromas and grape, berry, and ripe blackberry flavors.

For something sweeter and more aromatic, the Strawberry Candy Gesha blend pairs Panama Geisha with a Costa Rican raisin-honey-process coffee, so you get grape, raisin, rose, and strawberry-chewy-candy sweetness with soft fruit acidity and an almond finish. The Costa Rica Mozart, made with an innovative raisin-honey process that pre-dries the fruit on raised beds before the honey steps, delivers osmanthus, pineapple, and raisin notes and works for pour-over, cold brew, or the moka pot.