Breeding coffee for quality: an interview with Dr. Verônica Belchior
Understanding coffee quality and how it fits into breeding the varieties of the future with WCR’s Research Scientist for Quality Evaluation
Coffee quality is a primary driver of consumer preference, brand identity, and commercial value in today’s global industry. As overall demand grows, markets pursue increasingly differentiated products, and the climate crisis reshapes the growing environment, World Coffee Research (WCR)'s breeding program is refining its approach to quality and how to develop new varieties that meet consumer and market needs.
In this interview, Dr. Verônica Belchior, Research Scientist for Coffee Quality Evaluation, shares more about how the organization conceptualizes coffee quality and what approaches its scientists are using to assess and predict quality when breeding.
What is coffee quality? How does the understanding of that term change if you are a cupper/buyer, cupper/roaster, food scientist/product formulator, or coffee breeder?
VB: I’d say that quality, in its essence, refers to something that is distinguished or "good enough" for a specific market or purpose. When we talk about coffee quality, this definition becomes particularly nuanced, as it depends heavily on the perspective of different actors in the coffee chain. For coffee cuppers/roasters, quality is defined by the complexity, sweetness, cleanliness, intensity, and richness of aroma and flavors in the beverage. They also consider the absence of defects in a beverage that meets minimum market requirements.
Coffee buyers, comparatively, focus on the appearance of green beans, screen size, price, and organoleptic aspects that align with their purchasing intentions. The quality approach of food scientists examines it from a consumer perspective, prioritizing acceptability and preference. They may also analyze desired chemical compounds with significant health impacts or characteristics relevant to industrial processing. Finally, there are the coffee breeders. Their definition of quality encompasses the performance of the coffee plants, including physical characteristics of the beans, uniformity of flowering and ripeness, yield, and the plants' susceptibility to pests and diseases. Importantly, breeders also consider beverage quality, aiming for specific organoleptic characteristics that meet a defined market baseline, and they work to improve it. As you can see, "coffee quality" is not a singular concept, but rather a multifaceted one, shaped by the diverse objectives and roles of those involved in bringing coffee from farm to cup.
Dr. Verônica Belchior at WCR's research farm in El Salvador.
What is unique/different about the way that breeders think about quality vs. say, a cupper? What do breeders have to consider that others in the chain don't necessarily think about?
VB: Understanding coffee quality truly requires considering the different roles in the coffee chain. Coffee cuppers are central to defining beverage quality. They rely on a refined sensory library to evaluate and pinpoint quality attributes in the cup, identifying them across various factors like coffee varieties, origin, harvesting and post-harvesting methods, and roasting profiles. Coffee breeders, in turn, must interpret this quality definition from the cuppers. Their goal is to determine whether these desirable attributes in the beans are primarily due to genetics or a combination of environment and agricultural management.
Heritability is important for breeders to consider to make sure they are focused on the elements of quality that are genuinely influenced by the underlying genetics of the plant, and not due to other factors like processing, for example. Understanding the interaction between genetics and environment is also important because coffee quality and other attributes can vary significantly based on this interaction.
How does evaluating quality change if you are thinking about one sample—or even 100 samples—vs. thousands of samples?
VB: Well, it changes because of the significant effort that is required to evaluate coffee quality. Imagine this: professional cuppers might assess around 50 coffee samples in a single day (the number can vary). The process is incredibly detailed and time-consuming. Each sample goes through an extensive protocol to really dig into its individual characteristics. Now, let’s think about the challenge of evaluating thousands of samples. To get through that many samples, you'd need not just a few cuppers, but a whole team and a significant staff working for days on end. And the more samples you have, the harder it becomes to maintain accuracy and consistency throughout the entire evaluation. Achieving reliable results for coffee quality demands a big investment in both effort and resources, so we are exploring approaches that we can do this in a more targeted and efficient way.
WCR research scientists Dr. Jorge Berny and Dr. Verônica Belchior inspect robusta trees at the WCR research farm.
Can you explain further what sort of approaches you’re using?
VB: Breeders can actually predict coffee quality, and it all comes down to data! By using the definition of quality established by professional cuppers, we can differentiate coffee samples based on their chemical composition. How do we do this? We leverage high-throughput methods like spectroscopy and chromatography, combined with statistics. This allows us to, in a sense, "predict" coffee quality without having to cup every single sample. However, using these methods effectively isn't a quick fix. It requires a significant investment of time and a considerable amount of data. We need to collect and analyze information on quality, spectroscopy, and chromatography over several years, identifying consistent patterns that differentiate high-quality samples from others. It's a big undertaking, but the insights gained will be valuable for breeding efforts.
Breeding takes a very long time—decades. How have quality considerations historically been incorporated into the breeding process, and what is different about the way WCR is thinking about it?
VB: Historically, coffee quality has only been assessed at the very end of breeding programs, when a new coffee variety is almost fully developed. As you pointed out, breeding is a long process. If we don't evaluate quality alongside other traits throughout the development of a new variety, we risk overlooking valuable genotypes that could offer superior quality down the line. At WCR, we believe quality is a critical trait that deserves attention from the very beginning of our breeding programs, not just at the end. This means we are evaluating the quality at every stage of the process, right from the initial breeding parents. While our final varieties are not ready yet, we are putting significant effort into characterizing our material and refining our methodologies for assessing coffee quality. We are also developing robust statistical models to predict quality. These models will be an essential tool, allowing us to confidently screen thousands of candidate samples for quality when the time comes.
What are you most excited about in your work right now?
VB: I think being a part of the breeding program at WCR is fascinating! Getting to taste incredible coffees is just the beginning. I also get to deeply consider every aspect of coffee quality, from agricultural management to processing, and everything in between. It's a unique opportunity to understand the industry's needs while simultaneously working at the forefront of scientific research. Honestly, being part of an organization dedicated to securing the future of coffee is the most exciting part of it all.