Agriculture and Environment: Coffee

Better Management Practices: Reduce Water Use in Processing

Coffee production should minimise water use and prevent water pollution to the greatest extent possible.

Both Colombia and Costa Rica are experimenting with low-effluent processing systems that are said to produce coffee of a comparable quality to that of a traditionally washed product. This technology should be encouraged.

Productive use of waste such as pulp
Processors should screen and recycle the water that they use so that less water is used overall and less organic matter is put into rivers. Saving the pulp to compost or to use as mulch will both increase the organic matter in the soil and help the soil retain more water. These two factors will increase production.

Encourage anaerobic fermentation
One way to reduce waste is to encourage anaerobic fermentation before washing occurs. This process can decompose mucilage on the seed and makes it easier to wash. An added benefit is that it takes less water to wash the seed as well. This strategy is cost effective for processors but the technology is not well known.

Much of the coffee pulp in Costa Rica is put into windrows for drying and composting even though it can take up to 6 months for full composting to occur. However, coffee processors have found that by inoculating the waste with microorganisms they can reduce the compost time to less than 3 months. The compost is then returned to the associate growers.

Introducing microorganisms
Effective microorganisms are also being introduced directly into the processing stream so that effluents are largely decomposed by the time the wastewater leaves the plant. The microorganisms digest the waste and speed up the overall decomposition. This reduces the total amount of organic matter with high biological oxygen demand released into local waterways.