Penagos UCBE pulpers, an acronym for Unidad Compacta De Beneficio Ecológico or in English, Compact “Ecological Benefit Unit."
Coffee research centers and equipment manufacturers continue to look for ways to improve coffee processing techniques amidst a growing worldwide demand. With the acceptance, at least within the coffee sector, that climate change is real, these innovators also sought ways to reduce the use of water and to minimize the pollution wet milling creates.
Equipment suppliers took note of growers’ and millers’ needs to optimize production at all levels of quality. Energy efficient, low water consuming technologies for processing cherry into multiple grades of coffee are available now.
As numerous trials have shown, roasters’ concerns that drier milling might have a negative impact on quality are unfounded.
One such project at the Coffee Research Experimentation Center in Lao PDR, compared the cup quality of coffees processed in three ways in 2005/06. The researchers used a Vinacafe MXT Drum Pulper and MDN-0.5 Demucilager from Vina Nha Trang to wash arabica and robusta coffees for the “machine washed” beans in the trial. A key finding was that cup quality for each coffee did not differ significantly as a function of how it was processed.
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However, despite such evidence and the availability of equipment that uses significantly less water than first generation wet processing facilities, many existing mills still use large volume fermentation tanks or do little to prevent waste water from polluting natural water sources.
Many at the top end of the coffee value chain—consumers, baristas, roasters, and green buyers—struggle to understand why the newer technologies are not being purchased. A number of initiatives are underway to show how investing in the latest generation of pulpers and demucilagers makes economic and environmental sense. Though change is moving slower than many had hoped, if successful, these projects will open new market categories to farmers.
Carlos Brando, director of P&A Marketing which exports Pinhalense equipment
Barriers to Adoption
Fewer than 15% of coffee mill operators use “dry” pulping, according to Paul Hicks, water resources coordinator at Catholic Relief Services (CRS). Ask the question, “Why aren’t more mills moving to these newer systems?” and an impassioned discussion about underlying issues is bound to ensue. As with many sustainability topics, awareness of the political, economic, and cultural issues involved has not yet been enough to overcome such obstacles.
The prices for the ecological “dry” coffee mills vary; though tend to cost around $1,000 at a minimum (all amounts in this article are USD). That price may seem low to some in the coffee value chain. It is, however, out of reach for many small holders who still struggle to finance what they need to keep trees healthy and producing.
Hick’s colleague Michael Sheridan, coffee advisor for CRS, wrote about the economic and policy barriers preventing wider adoption of new wet mill technologies in 2012. Sheridan’s post focused on regulatory and economic barriers in Central America, however many of the same issues exist for all coffee-growing regions.
Hicks and Sheridan are far from alone in trying to understand why more operators have not upgraded equipment. Carlos Brando, director of P&A International Marketing, that exports Pinhalense equipment to 92 countries, is an expert on milling equipment, has a background in sanitation engineering, and is a frequent consultant to organizations including the International Coffee Organization (ICO) and the World Bank.
About water use laws, Brando said, “What most countries have is legislation that may be tougher or less tough on the composition of waste water you can throw in the rivers.”
Sheridan noted that “… [Awareness] of existing public standards is deficient and enforcement uneven. There are few consistent positive incentives to adopt new technologies.”
Traditional cultural practice remains a barrier in many places as well. Referring to experience with the CAFE Livelihoods project, Sheridan reported, “During the first harvest after the processing centers were installed, only two were used to process any substantial portion of the coffee belonging to the cooperatives that operated them. … Over time, all 10 cooperatives adopted, but only gradually, and with a full subsidy for technology acquisition and technical support.”
Ipanema coffee pulping facility
Coffee mill advances over time
The history of innovations in coffee processing stretches back to the time of the Industrial Revolution. Two companies selling pulpers today are over 100 years old: multinational Marshall-Fowler Group (MFG), known for its tea and coffee equipment, got its start as Marshall, Sons & Co. in 1848; and Penagos Hermanos in Colombia was founded in 1892. Newer equipment makers like Pinhalense in Brazil and Vina Nha Trang in Vietnam established their reputations in the second half of the 20th century.
The mechanical siphon, patented by Pinhalense, was one of many advances made in the late 1970s used widely in current systems. Mechanizing the removal of mucilage was another. As such changes were tried and introduced, consumers’ coffee tastes also evolved. Today, mill operators may find themselves pulping for multiple markets and may even be asked to handle arabicas and robustas, fully washed and semi-washed in one facility.
Pinhalense has improved upon its first generation components which were first available decades ago. Notably, in the 1980s, the company introduced unripe/green cherry separation equipment that enabled processers to pulp, i.e., to remove the skin from only ripe coffee cherries with the further choice of leaving all or some mucilage behind or removing it all. Once dried, those semi-washed or washed coffees are prized for their unique flavor characteristics.
Originally developed for Brazil, green cherry separation and pulping systems were subsequently introduced around the world as the quality of selective picking decreased and partially ripe and unripe cherries started to be picked in larger quantities. Pinhalense’s green separators discriminate between unripe, under-ripe, and ripe cherries and decide which ones to pulp to achieve the highest quality with an optimum cost-benefit.
“Reduction of water consumption and contamination is a relatively new but very important concept,” said Brando. “As its name indicates, washed coffee used to consume and contaminate a lot more water than it does today. Some equipment suppliers even claim that their machines do not consume water at all but the real question is if such machines are indeed used without water and then what is the extent of damage to coffee this may cause,” he said. Pinhalense wet mills require a very limited amount of water in order to ensure nearly zero loss of parchment coffee with the pulp that is discarded and minimal or no physical damage to coffee.
Cenicafé the research arm of the Colombian Coffee Growers Federation (FNC), began investigating techniques known today as dry pulping during the 1980s. Scientists there spent a decade and a half in research and development before testing their first commercially available ecological milling system, Becolsub. More recently, they debuted Ecomill which is available in three sizes.
Researchers reported Becolsub reduces contamination due to milling waste water by 90% and Ecomill closes the 10% gap eliminating waste water contamination. A press release summarizing Ecomill’s capabilities stated, Ecomill can save 35,000 liters of water, the amount used by 233 people each day, for every 1,000 kg of coffee that is processed.
Penagos created a line of pulpers called DCV, short for despulpador a clasificador a de verdes or in English “green sorting pulper,” and another called UCBE, an acronym for unidad compacta de beneficio ecológico or in English “compact ecological benefit unit.” Each incorporates features designed to use less power and water. For example, the DCV is best suited to pulping when 5-50% of the cherries may be under-ripened (hence the reference to “green” in the name). Penagos is in the process of making refinements to its latest designs, which are not yet available, after surveying attendees at the Specialty Coffee Association of America Exposition in Seattle this year. Alfonso Penagos, international coffee division sales director at Penagos, said, with the DCV, “a rubber device located on the top part of the pulping channel ‘knows’ when a ripe cherry must be pulped and when a green cherry not.”
While each organization’s system differs in the amount of power and water necessary to function, most use similar processes and techniques. Wet mill designs now incorporate mechanical or vertical siphons, green cherry separators, screen pulpers, and repassers to optimize water use. Many also use sieves, screens, and screw conveyers.
The benefits of the latest generation of pulpers includes less loss of parchment coffee in the pulp, little to no physical damage to parchment, and lower water consumption. Also, less physical space is needed for many models.
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Photo by Dan Bolton/STiR Tea & Coffee
There are now 60 Ecomills operating in Colombia. This smaller version is located on a coffee farm in Caldas near Marizales.
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Photo courtesy Pinhalense
A mechanical siphon, green cherry separators, repass pulpers, and mucilage remover in El Salvador.
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Photo courtesy Pinhalense
Pinhalense wet mills in India
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Photo courtesy Pinhalense
Loading cherry into a FNC Ecomill 3000
More progress on the way
In spite of the barriers to adoption of drier wet mill systems, trial projects and production-ready deployments continue in coffee-growing regions around the world. Work is already underway in Asia, Central and South America.
In one case, a large Brazilian processor and exporter updated equipment to produce better beans for export. Ipanema Coffees switched to using equipment from Penagos’s DCV line in 2014. Ipanema tested the new processing system for one whole season before announcing in a press release in May that “…all the initial promises of increasing productivity and improving quality have been fulfilled.”
Indian grower and exporter BBTC uses the latest Pinhalense wet milling equipment to process arabica and robusta coffees that have received quality awards in India and abroad and have been selling for premium prices. The little waste water produced is used to generate biogas for the Pinhalense driers.
The FNC has been promoting Ecomill to its membership since announcing its availability in 2013. According to Carlos Oliveros, principal investigator at Cenicafé, there are 60 Ecomill systems of varying sizes in use on farms and in coffee processing facilities in Colombia. Three completed projects—Ecomills in the Center of Cañasgordas; in the Risaralda region; and in Argentina, Huila—will serve a combined total of about 445 coffee producers. One under construction now has the capacity for receiving more than 180,000 kg of coffee cherries and to meet the needs of at least 200 small coffee producers.
Oliveros said, “As you can see, there is a significant increase of small coffee producers’ use of technology for [processing coffee].”
Brando also observed that as his customers convert existing mills to newer, drier coffee processing equipment they experience water use reductions. Some also repurpose fermentation tanks to treat water either for reuse in the mill or for farm irrigation.
The current and next generations of ecosystem-friendly “dry” pulpers could enable small farmers to provide coffees of the quality specialty buyers expect with less pollution than was possible before. This win-win scenario might well be a key part of creating and sustaining greater economic independence for growers and the workers they employ.
However, the industry as a whole needs to continue applying pressure to create legal and economic incentives, or to encourage enforcement of water quality regulations where they exist, if a general movement towards drier wet processing is to happen.