Coffee Quality from Seed to Cup
This idea of quality as adherence to specifications is largely what guides the concept of quality in coffee. The specifications or client requirements are variable. Thus, definitions of quality vary depending on the context and priorities. Certification schemes, marketing and price all play a defining role, but quality ultimately dictates the worth or price of a given coffee. It is the attribute that positions coffees within a certain market segment. In specialty coffee circles, quality combined with rarity is the holy grail.
Coffee quality assessment tools and methodologies are about finding a common language and set of indicators to evaluate coffee. These methodologies are informed by research and science. However, the descriptive sensory analysis stage remains a qualitative assessment that is difficult to measure. There is no perfect system, and coffee quality assessment methodologies are constantly evolving as new research and technologies become available – and as the coffee industry itself evolves.
Who assesses coffee quality?
Accepted parameters for flavour quality assessment today are based on the culturally preferred flavours of Western Europe, North America and Japan – the three biggest global coffee markets. These systems are more rooted in the industry’s habits and practice than in a clear body of research. It is based on the preferences of coffee tasters, which may or may not be relevant to a given set of consumers.
While emerging coffee consumer markets have widely adopted the cultural preferences of traditional coffee markets, this is changing. Traders are looking at marketing specific coffees to defined groups. Thus, quality evolves with changing consumer preferences, demographic shifts in buying power and greater knowledge of how flavours and aromas interact with human physiology and psychology.
Coffee quality is generally evaluated in two ways: a physical evaluation of the green and roasted coffee, and sensory evaluation of the roasted beverage. This assessment detects potential physical, chemical, anatomical or functional defects. The goal is to avoid defects in the final beverage and to discover the attributes in the coffee cup.
Over the years, green coffee quality classification systems have evolved, due to buyer demand for higher quality coffees. This has catalyzed a new experimental sensory journey and new food safety considerations.
Cupping
Professional cupping has been the quality-control practice that has determined both market access and market value for at least 100 years. An activity that relies on an individual’s senses has been made as objective as possible, thanks to sensory and food science, training and screening sensory panels, and alignment with and calibration to standards.
Coffee is evaluated through a method called cupping, a sensory analysis that follows specific protocols at various levels. For green coffee buyers, it helps determine purchase decisions, while roasters use it to fine-tune roast profiles. Quality-control specialists rely on cupping to ensure consistency and defect-free coffee.
Cupping standards vary but typically focus on detecting defects and grading coffee based on aroma, flavor, and mouthfeel. The process involves a structured evaluation of the coffee's aroma, taste, and texture, with attention to bean color, roasting, grinding, and brewing techniques, ensuring a comprehensive sensory experience.
The taste of great coffee is in the grinding
The aroma of a cup of coffee is the final olfactory expression of a long chain of transformations that link the seed on the tree to the cup on the table.
It takes a full year of dedication and work, from the start of the new harvest to roasting the beans, before the coffee finally ends its journey. When the roasted beans arrive in coffee shops and homes, all that remains to enjoy an exceptional cup is grinding and extraction.
These last few minutes are the make-or-break moment. Understanding and mastering grinding and extraction guarantees that the full flavour of the beans tickles our taste buds. It also shows respect for the devotion and effort that went into producing and transporting the coffee.
Grinding and extraction are interconnected and complicated processes. Considering the complexity of these transformation steps, it is important to simplify and structure research strategies.
Researchers distinguish between input parameters and output variables.
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Output variables are elements of the overall consumer experience related to the perceived quality. These include flavour profile, body, crema (for espresso) and cup-to-cup consistency.
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Input parameters are thought to have an impact on output variables. These can be divided into three categories: those related to the coffee itself, the water, and the extraction technique.
The goal of research in this field is to find quantitative and accurate relationships and models that can predict output variables from input parameters combined with specific extraction techniques. Understanding how these input and output factors interact enables optimal calibration for maximum flavour.
Useful tools and resources to navigate the coffee industry
Whether you're a producer striving to enhance your crop or a buyer looking to refine your sourcing criteria, these resources provide essential insights into what makes exceptional coffee stand out on the global stage.
The catalogue provides information to farmers and other renovation or planting decision-makers so they know what Arabica variety is best for their situation, taking into account agronomic data, i.e expected yield, nutrition requirements optimal altitude, disease and pest resistance.
This atlas provides habitat suitability maps for 54 species that are widely used in Central America for shade in coffee or cocoa agroforestry systems. These species represent 24 fruit species, 24 timber species and 6 species used for soil fertility improvement.
The EAC Quality for Trade Platform is a one-stop shop providing information about quality regulations, standards and buyer requirement. ITC developed the platform under MARKUP with the support of the European Union in collaboration with the EAC Secretariat. Through its interactive modules, such as the Quality Compass and the Quality Connect, the platform gives an opportunity to connect with relevant institutions and individuals, seek pathways to improvements and gain insights from peers.
The mysterious origins of Chiroso coffee
Almost all cultivated coffee varieties in the world can be traced back to Yemen. Although wild coffee originates in Ethiopia, it is in neighbouring Yemen, a short hop across the Red Sea, that coffee was first recorded as a cultivated crop and brewed as a beverage.
However, DNA analysis has revealed that some coffee varieties appear to be directly related to their Ethiopian wild forebears. One example is Chiroso in Colombia.
‘In recent years, I heard of a new, mysterious variety name from Colombia: Chiroso,’ recalled Christophe Montagnon, a coffee breeding expert and chief executive of RD2 Vision, which provides tropical farms with agronomic and other services, including DNA fingerprinting. ‘Friends in Colombia were whispering that the quality was great, maybe unique, maybe outstanding with lemon, mango and other exotic aromas.’
Carmen Cecilia Montoya Patiño first spotted a few mysterious trees that she thought would be interesting to cultivate. She took some seeds and grew them on her farm, winning the Cup of Excellence in 2014. Eventually, the tree received the name Chiroso, which means ragged or tattered. ‘This name comes after the appearance of the leaves of Chiroso in the dry season,’ Montagnon explained.
Genetic sleuthing
Felipe Henao, a farmer from Antioquia, won the Cup of Excellence with Chiroso beans in 2020. This is when Montagnon was introduced to the mysterious variety.
Intrigued to find out the roots of Chiroso, Montagnon embarked on a genetic quest to plot its family tree. ‘I wanted to know more and got some beans of Chiroso to run a DNA fingerprint of the variety,’ he said. ‘The result gave me this unique emotional thrill as a researcher when you find something unexpected but significant.’
The results of the study, which were published in the international journal Genetic Resources and Crop Evolution, blew Montagnon’s mind. ‘Chiroso appears to be an Ethiopian landrace, different from the vast majority of coffee varieties that conquered the world through Yemen,’ he explained, noting that it is genetically different from the better-known example of an Ethiopian landrace, Gesha.
‘Chiroso is bringing huge novelty,’ he said. ‘It is a dwarf variety, hence different from Ethiopian landraces known outside of Ethiopia, which are all tall. ‘[This] opens very interesting perspectives for growing practices of such a high-quality variety.’
Source: Christophe Montagnon, Founder and Chairman, RD2 Vision (2021)
Reviving Robusta production through collaboration and innovation
In 1990, Robusta coffee produced by members of the Agency of Robusta Coffees from Africa and Madagascar (ACRAM) represented an impressive 25% of world coffee production. In 2010, that number had plummeted down to just 5%.
ACRAM member states never recovered from the economic crisis that hit Africa in the 1990s. Agricultural inputs became more expensive and less accessible, cultivation techniques became unsuitable, producers lost motivation to keep up activities and production decreased enormously.
A common multiplication technique in ACRAM countries is the use of root cuttings, often produced hundreds of kilometres away from nurseries. Ultimately, it has an average success rate of only 20%, a huge demotivator for any producer.
ACRAM took the lead in finding solutions and boosting Robusta production. In the framework of its scientific conference, research institutes from Côte d’Ivoire (CNRA), Cameroon (IRAD) and Togo (ITRA) joined forces to revamp the sector and innovate.
The CNRA signed a convention with the IRAD on technology transfer. As a result, since 2015, the much more effective multiplication technique of direct tunnel cuttings is practiced in Cameroon, Togo and Côte d’Ivoire.
In Cameroon, the use of direct tunnel cuttings is being mainstreamed and nursery success rates have shot up from 20% to 90%. A 100% success rate is not uncommon.
Thanks to cross-country cooperation, the future of Robusta in Africa and Madagascar no longer looks bleak as ACRAM plans to replicate this technique across the region. Sharing knowledge, experience and resources will enable innovation, increased competitiveness and long-term growth.
Quality: Assumptions, expectations and risks in the producer-roaster transaction
Quality is a relative concept, and perceptions of quality vary across the board. This can create some disappointments, especially in producer-roaster transactions.
Paul Arnephy, co-founder of Lomi Roastery and Café in Paris, relates a salient anecdote. He and his team are working with a cooperative in Peru to produce a coffee blend. After a few exchanges, they finally arrived at a flavour profile that was ideal for their needs, considering the price and volume requirements for both parties.
Excited about this cooperation, they were met with some disappointment when the coffee finally arrived:
‘When the pre-shipment sample arrived, it tasted nothing like the offer lot we had agreed upon. There was much more acidity and fruit forward flavours than we had requested.
‘After discussing with the cuppers at the cooperative, we realized what had happened. They had changed the profile by adding more acidity because they thought it made the coffee higher quality. They thought we would be really happy with the surprise.’
However, the coffee was no longer on profile and was actually less valuable to Lomi. Roasters often do not realize that quality is a relative concept and that what they consider to be an outstanding profile might not be considered so by the producers themselves.
That is why open communication and conveying as much detail and explanation as possible during a transaction – if the circumstances allow it – is paramount.
Source: Paul Arnephy, co-founder Café Lomi
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