How Coffee Beans are Processed and Go From Harvest to Brew

Key Takeaways

• Coffee processing starts with the harvesting of ripe coffee cherries.
• Three main methods of processing affect the beans' flavor differently.
• Drying, milling, and roasting steps are essential for final coffee preparation.

There are three primary methods of coffee processing: washed (wet), natural (dry), and honey processed. Each method involves different steps and techniques, influencing the final taste of the coffee in unique ways. Understanding these methods helps us appreciate the diverse flavors that different coffees offer.

Once processed, the beans are dried, milled, and roasted. These steps refine the beans further, readying them for brewing. From sorting to roasting, every stage is crucial to enhancing the coffee's character and delivering a rich, aromatic cup that we enjoy daily.

Processing Methods

The ways in which coffee beans are processed can greatly impact their flavor profile. Each method has its unique steps and techniques, influencing the taste, aroma, and overall quality of the coffee.

Dry Process

The dry process, also known as the natural process, is one of the oldest methods. We lay the harvested coffee cherries out in the sun to dry, leaving the fruit flesh intact. This method requires regular turning to avoid spoilage.

During this period, the beans absorb sugars and flavors from the surrounding fruit, resulting in a sweeter and fruity profile. The drying process can take several weeks, depending on the climate. Once dried, the outer layer is mechanically removed to reveal the beans.

This method is labor intensive due to the constant need for monitoring and turning. Still, it’s highly valued for the complex flavors it can produce.

Wet Process

Also known as the washed process, wet processing involves removing the outer fruit layer before drying. We start by pulping the cherries to separate the beans from the fruit. The beans are then placed in water filled fermentation tanks to remove the mucilage.

Fermentation can last anywhere from 12 to 48 hours based on the desired flavor outcome. After fermentation, the beans are washed to remove any remaining residue. Finally, the clean beans are dried, either in the sun or using mechanical dryers.

Wet processing usually results in a cleaner, more acidic cup of coffee with vibrant notes. This method tends to highlight the intrinsic flavors of the beans, making it popular for high quality coffee varieties.

Honey Process

Honey processing is a hybrid between dry and wet methods. We pulp the coffee cherries, removing most of the fruit but leaving some mucilage on the bean. This sticky layer, or "honey," adds sweetness to the beans during drying.

The drying process can vary, and the amount of mucilage left can be controlled to produce different flavors, such as "yellow," "red," or "black" honey, indicating the degree of mucilage left and drying time.

This method combines the best of both worlds: the fruity notes of the natural process and the clean finish of the washed process. However, it requires careful management to avoid spoilage due to the remaining mucilage.

Semi Washed Process

The semi washed process, also referred to as the pulped natural process, involves partially washing the beans. After pulping, we skip the fermentation step and immediately dry the beans with some mucilage still attached.

This method reduces water usage and shortens processing time. The beans are spread out to dry in the sun, often on raised beds to improve airflow and reduce mold risks. This process produces beans with a balanced profile, featuring both the clarity of wet processing and the sweetness of dry processing.

By balancing the components of both methods, the semi washed process aims to achieve a harmonious flavor, making it a favored technique in regions where water is scarce.

Drying and Resting

Drying and resting are critical steps in coffee processing that involve reducing moisture content and stabilizing flavors. These processes ensure the coffee beans maintain their quality and develop the desired taste profiles.

Drying Techniques

Drying is essential in preserving the quality of coffee beans. The primary goal is to reduce the moisture content to around 10-12%. There are various techniques used:

1. Sun Drying: Coffee beans are spread out in thin layers on drying beds or patios and are turned regularly for even drying. This method can take several days to weeks.

2. Mechanical Drying: Specialized machines use hot air to speed up the drying process. This method is quicker but requires careful temperature control to prevent damage.

Different processing methods affect drying. In natural processing, beans dry with their fruit skin intact, enhancing fruity flavors. Wet processed coffee involves removing the fruit layers before drying, often resulting in cleaner flavors. Similarly, honey processing leaves some mucilage on the beans, imparting unique tastes during drying.

Resting and Storage

After drying, coffee beans need a resting period, also known as stabilization. During this phase, beans, also called parchment coffee if the parchment layer is still intact, are stored in a controlled environment to further stabilize moisture and develop flavors.

Resting times vary but typically last several weeks to a few months. It is crucial for allowing the beans to settle and balance their internal chemistry. Consistent temperature and humidity levels are maintained during storage to prevent mold and preserve the beans' quality.

We store beans in jute bags or GrainPro bags that offer additional protection against environmental factors. Proper resting and storage ensure that when the beans are finally roasted, they produce optimal flavors and aromas.

Milling of Coffee

Milling coffee beans involves several important steps to prepare them for roasting and brewing. These include hulling, polishing, and grading and sorting the beans.

Hulling

Hulling is the process of removing the outer layers of dried coffee cherries or parchment coffee. When dealing with wet processed coffee, we remove the tough parchment layer, known as the endocarp.

For dry processed coffee, the entire dried husk, which includes the exocarp, mesocarp, and endocarp, must be removed. Specialized hulling machinery is utilized to ensure this is done efficiently without damaging the beans. Proper hulling is essential for achieving high quality green coffee beans that are ready for the next stages of coffee production.

Polishing

After hulling, some coffee beans may undergo a polishing process. This involves removing any remaining silver skin from the beans' surface. While polishing is an optional step, it can improve the beans' appearance, making them shinier and more appealing.

Some coffee producers skip this step as it is considered unnecessary for the flavor profile. However, for those who choose to polish their beans, it adds an extra touch of refinement, especially for specialty coffee production.

Grading and Sorting

The final stage in milling is grading and sorting the beans. This process ensures that only high quality beans make it to the market. Beans are graded based on size, weight, and color. Defective beans are removed to guarantee that only the best beans are used for roasting.

Sorting is often done using machines, but manual sorting is also common, especially in specialty coffee production. This careful examination helps maintain consistent quality, enhancing the flavor and overall experience for coffee lovers.

By carefully hulling, polishing, and grading and sorting coffee beans, we ensure that what ends up in your cup is of the highest quality, providing a delightful coffee experience.

Coffee Roasting

Roasting coffee beans is crucial for developing their unique flavors and achieving desired qualities. It involves various levels and techniques to determine the final aroma, body, and acidity.

Roasting Levels

Coffee roasting levels range from light to dark. Light roasts preserve more of the bean's original flavors, often resulting in a brighter acidity and lighter body. The first crack is a key milestone, where beans make a popping sound, signaling the beginning of roasting changes.

Medium roasts balance between preserving original flavors and developing new ones. These roasts have a more balanced acidity and a slightly fuller body. They are often preferred for their harmony of flavors.

Dark roasts are heated until the second crack, where beans release more oils, leading to a bold, robust flavor. These roasts usually have lower acidity and a heavy body. They sometimes develop smoky or burnt notes, losing some original bean flavors.

Flavor Development

The temperature and duration of roasting greatly influence the flavor profile of coffee. During the roasting process, chemical reactions occur, transforming green beans into aromatic brown beans.

At lower temperatures, beans may develop fruity and floral aromas. Higher temperatures typically enhance caramelization and Maillard reactions, which create deeper, sweeter flavors and increase the body of the coffee.

Consistency is key in coffee roasting to achieve the desired flavor profile. Roasting machines help control the consistency by evenly distributing heat, ensuring uniform color and flavor development throughout the batch.

By mastering roasting techniques, we can produce high quality coffee with specific taste characteristics, meeting various preferences and standards in the coffee industry.