My customers seem very interested in shade-grown coffee. Why does it matter?! How does it impact the coffee quality? Shouldn’t I just advise them to judge specialty coffee by its flavor?
South Bend, IN
There are many factors that make coffee valuable to consumers. Shade matters to some from an environmental perspective; others because they feel it influences the flavor. What do we actually know about these important issues?
The good news is, much research has been done on the ecological and economic impacts of shade-grown coffee. Sadly, there is far less information available on how this influences cup quality. When we hear the term “shade-grown” coffee we many imagine a pristine ecosystem where coffee just happens to be planted and coffee farmer happen to be walking around in the woods picking the beautifully ripe coffee they stumble upon. This romantic vision is rare in the coffee industry. There are, however, varying definitions and variations of forested coffee and agroforestry to consider when thinking of purchasing or promoting such a coffee.
Trees and agroforestry can provide environmental advantages to the planet, and simultaneously in coffee production. Trees act as carbon sinks in the landscape, make oxygen, save water, and provide a myriad of other benefits to the local microclimate and ecosystem. Trees provide the ecosystem with structural and chemical resources. Their roots help prevent erosion. They offer the soil much-needed nutrients from their fallen litter, and certain species can fix nitrogen from the air (Souza and others 2012; Romero-Alvarado and others 2002; Dossa and others 2008; Munroe and others 2015).
Trees act as buffers to the coffee microclimate. That means that they can act as insulators for the understory, where coffee grows. They can both protect coffee from frost as well as cool the microclimate during very warm weather (Souza and others 2012; Santos and others 2012). Another large way that trees regulate microclimate conditions is through holding moisture in the ecosystem, leaving more water in the soil and therefore theoretically available to coffee plants. There is also evidence that tree cover reduces the leaching of nitrogen from the coffee plantation (Tully and others 2012).
There is a large body of literature supporting the idea that when shade is added to a coffee-growing system, the biodiversity of the ecosystem increases (Perfecto and others 1996; Romero-Alvarado and others 2002; Soto-Pinto and others 2001; De Beenhouwer and others 2013; Jha and others 2014). Here we should stop, and remember that biodiversity is an important intrinsic value. It is a choice to recognize and care about biodiversity. While many of us hold this value, the challenge is to quantify the value of it. How much “better” is a coffee that is produced in a highly diverse environment? Our community faces this challenge daily.
What about flavor: can we taste shade-grown coffee? The answer varies depending on the individual situation. What we do know is that generally, the smaller coffee yield under shading leads to fewer, larger coffee fruits. Also, there is evidence that shade-grown coffee seeds have higher sugar and lipid contents than sun-grown coffee, which may increase the cup quality of coffees (Alpizar and others 2004; Geromel and others 2008; Vaast and others 2006; Somporn and others 2012; Marraccini and others 2005; Bosselmann and others 2009). Multiple studies have found that the acidity and body of brewed low-altitude coffee was improved by shading (Muschler 2001; Vaast and others 2010b; Vaast and others 2006). They suggested that a lower growing temperature (provided by shade) produced a more uniform ripening of berries, which led a better quality cup. However, there are also conflicting studies that have found no perceivable difference in quality (Steiman and others 2006; Vaast and others 2010a). What is the problem here? In the end, unless we understand the biochemistry of fruit ripening time and how this directly affects the chemical composition of coffee seeds and link this to repeatable and consistent flavor differences, it is impossible to say with certainty what is going on. That’s right folks—here is another example of why we reach this same conclusion again and again: more research is needed to help fully understand why coffee tastes the way it does!
Unfortunately, there can also be true drawbacks to shade-grown coffee. In many situations, shade lowers coffee yield (Steiman and others 2006; Vaast and others 2006; Morais and others 2006), delays ripening (Muschler 2001; Vaast and others 2006; Ricci and others 2011), and is more labor-intensive to harvest. These are luxuries that not all producers, as people who must balance costs and benefits, can choose. Any value or perception thereof must make business sense. Fortunately, some farms that use agroforestry can benefit from pricing incentives offered by certification programs. However, the reality is, that the value of shade coffee is not always translated into farmer benefit.
Where does this leave us? Certainly, flavor alone is not an indicator of whether or not a coffee was shade-grown. Great-tasting specialty coffee can be produced using many/any/all/unknown production strategies. There are real ecological benefits of shade-growing coffee, and there may be quality benefits too. However, if we seek to support this method of coffee growing, we must recognize and value it for its own sake.
So, Shady, the real question becomes, what is shade coffee worth to you?
Emma Sage is the science manager at SCAA, where she promotes research, acts as the primary liaison between science and industry, and serves as a scientific interpreter for coffee professionals. She holds a M.S. in Botany from the University of Wyoming, a B.A. in Ecology, and holds a post-graduate certificate from the Applied Sensory and Consumer Science Certificate Program at the University of California, Davis.
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