Coffee taste and aroma challenged by climate change, finds US study

27 Oct 2021 --- Coffee’s sensory qualities, such as taste and aroma, are being impacted by shifts in climate change. This is according to researchers at Tufts and Montana State University in the US who found that yield is not the only factor vulnerable to environmental shifts. 

Subtle changes in flavor notes, brightness, and other variables to terroir should also be taken into account.

“A subpar cup of coffee has economic implications as well as sensory. Factors that influence coffee production have great impacts on buyers’ interest, coffee price, and ultimately the livelihoods of the farmers who grow it,” says Sean Cash, a professor in global nutrition at Tufts and senior author on the study. 

The work published in Frontiers in Plant Science reviewed 73 published articles, examining the effects of 10 prevalent environmental factors. It also details current adaptation strategies that could combat these effects, providing hope for positive outcomes.

Factors affecting quality 
The most consistent trends the team found were that farms at higher altitudes were associated with better coffee flavor and aroma, while too much light exposure was associated with a decrease in coffee quality.

A synthesis of the evidence found that coffee quality is also susceptible to changes due to water stress and increased temperatures and carbon dioxide, although more research on these specific factors is needed.

Some current efforts to mitigate the effects of climate change show promise and feasibility, but innovative solutions to support bean growth at all elevations need to be devised, the team says. Shade management to control light exposure, selection and maintenance of climate-resilient wild coffee plants and pest management can all help to boost quality. 

“These strategies are giving some hope that coffee quality can be maintained or improved and will ultimately help farmers consider how to design evidence-based interventions to support their farms,” says Selena Ahmed, an ethnobotanist in the Food and Health Lab at Montana State University, who earlier was a postdoctoral scholar in the Tufts IRACDA program. 

“These impacts on crops are important to study in general, not just for coffee. Our food systems support our food security, nutrition and health.”

Keeping land for cultivation 
Coffee is grown on more than 27 million acres across 12.5 million largely smallholder farms in more than 50 countries. However, the amount of cultivable land for coffee is expected to be slashed by half by 2050, according to Joseph Rivera, global portfolio and innovation lead for coffee at Kerry. 

On International Coffee Day, he flagged that there has been an increased focus on research in developing alternative coffees due to the threat of global warming. 

Meanwhile, initiatives like The Gorilla Coffee Alliance, in collaboration with Nespresso and Olam Food Ingredients, are working to replenish land for coffee production in the Democratic Republic of Congo. 

“Climate change impacts on crops are already causing economic and political disruption in many parts of the world,” he says. “If we can understand the science of these changes, we might help farmers and other stakeholders better manage coffee production in the face of this and future challenges,” Cash concludes. 

Edited by Missy Green