Coffee processing has numerous nuances that seemingly provoke endless amounts of discussion. More than just sun-dried or mechanically dried, there are many types of driers, each with their own peculiarities. Here we look at some of the types of driers you will find mentioned in our information sheets or field trip notes.
Traditional (Non-Powered) Coffee Drying Methods
These methods rely on natural elements like sunlight and wind, making them energy-efficient and environmentally friendly.
Raised beds, EaTan, Vietnam
- Patio: Large flat surfaces, typically concrete or brick, where coffee is spread and sun-dried manually by raking throughout the day. The material used will affect the drying efficacy.
- Raised beds: Mesh platforms elevated off the ground to improve airflow and prevent moisture buildup, promoting even drying. These could be long tables or shorter ‘trays’
- Parabolic driers: Tunnel-shaped structures with plastic covers that trap heat and allow airflow, speeding up drying while protecting beans from rain.
Parabolic dryer drying cacao, Costa Rica
- Greenhouse: Enclosed structures using solar heat and controlled ventilation to dry coffee slowly and evenly.
- Ferris wheel: Rotating mechanical systems that move coffee trays in a circular motion to ensure uniform drying with minimal manual labour. Not common.
Local Innovation in Coffee Drying
- Casa Elba: A specialised drying house with adjustable walls and roof panels to control temperature and humidity. Often seen in Colombia, great for dealing with changeable weather.
Mechanical Coffee Drying Methods
These systems use heat—often from wood burners or recycled parchment—to speed up the drying process, especially useful in high-volume operations.
- Guardiola: A horizontal rotary drum dryer developed in Guatemala (by a Mr J Guardiola), where coffee is tumbled while hot air circulates through the drum, enabling fast, uniform mechanical drying
Rotary drier (Guardiola), Costa Rica
- Vertical Drier: A tall, column-like dryer where coffee descends slowly through heated air channels, often used for continuous drying in high-volume operations.
- Ecodrier: A vertical cylindrical dryer designed for energy efficiency and uniform drying, often incorporating stainless steel construction and eco-friendly heat sources.
- Flatbed Drier: A horizontal bed with perforations that allow warm air to rise through the coffee layer. This may have many layers to it as ‘tray’ that can be moved up or down.
Unique Coffee Processing Style in Quindio
- Patio Quindiano: An old regional Colombian method involving a flat, perforated drying bed with warm air rising from below and a mechanical paddle that moves along the bed to stir the coffee, enhancing airflow and uniformity.
Patio Quindiano drying bed, Colombia
Powered or unpowered, the choice for producers is often limited to what they have inherited, the landscape dictates, or even what is available in country. Some styles like the raised beds have become so synonymous with a region they have even leant their name. Whether by design or not, each method adds to the story and romance of the farm, as well as being a critical factor in the final quality.
