How science is making chocolate taste even better

Luisa Vicinanza-Bedi (right) and Colombian cocoa farmer Carmen Magali Eraso Adarme

Luisa Vicinanza-Bedi is an artisan chocolatier in Nottingham and the founder of Luisa’s Vegan Chocolates.

“I’ve always loved chocolate, but when I discovered all the flavors and nuances of single-origin chocolate, the incredible flavor notes, like a fine wine, was eye-opening,” he says.

Much of the chocolate we eat will be made from mixed cocoa from various farms, areas, or even countries.

But Ms. Vicinanza-Bedi argues that using just one variety of bean, from just one farm, gives the chocolate a unique flavor.

“We trade directly with our farmers and check the quality of the beans,” she says. “We do cut test, weight test, moisture analysis, pilot line aroma and taste test.”

Professor Irene Chetschik heads the Food Chemistry Research Group at the Zurich University of Applied Sciences (ZHAW)

Professor Irene Chetschik has developed a more controlled way of fermenting cocoa beans

“If you think about wine or coffee, it’s the same thing. The flavors come from the terrain, climate and soils in different parts of the world. They all taste amazingly different.”

Scientists are trying to analyze where those special flavors come from, so they can be reproduced more consistently.

Professor Irene Chetschik heads the Food Chemistry Research Group at the Zurich University of Applied Sciences (ZHAW).

She is developing new technological processes that can impact cocoa flavor at the molecular level, to get the best out of each harvest and create consistent quality.

“Now there is more appreciation for the product: we know where the bean comes from, which farm, which variety; we can experience a much broader diversity of flavors,” he says.

Traditionally, cocoa beans are fermented on the farm where they were grown.

Splitting a cocoa pod

Cocoa pods must be split to extract the beans which are then fermented.

Cocoa pods are harvested and cracked. The pulp-covered beans are piled or stored in baskets, covered with banana or plantain leaves, and left to warm in the sun.

Microbes present in the environment break down the pulp that surrounds the beans.

The beans are then dried, spread out on mats in the sun.

“Fermentation results in many differences in quality. Not all fermentations work well,” says Professor Chetschik.

Poorly fermented cocoa beans develop little flavor, while overly fermented cocoa beans produce a sour taste.

Cocoa beans fermented under palm and banana leaves in Vietnam

Once split, the cocoa beans are left to ferment, here they are covered with palm and banana leaves.

“Wet incubation” is a new fermentation technique, developed by Professor Chetschik and her team, in which cocoa beans are dried and then a lactic acid solution containing ethanol is applied.

“This triggers the same reactions within the beans, but it’s much easier to control,” she says.

The resulting flavor, he says, is sweeter, richer and fruitier.

Johannes Ansgar Schlüter, PhD student at ZHAW, adds: “The process provides a way to control the key flavor attributes of cocoa. At the same time, undesirable aroma components are not formed to the same extent as during traditional fermentations.”

Cocoa beans placed in a hole to ferment, on this farm in Mbau, Democratic Republic of the Congo

On this farm in the Democratic Republic of Congo, the beans are put into a pit to ferment

A better understanding of the fermentation process could help struggling farmers.

About 95% of cocoa is grown on small family farms, which employ some six million cocoa farmers around the world. With low yields and little power, the growing profits in the sector do not reach cocoa farmers and many farmers live in chronic poverty.

“The cocoa value chain is still unevenly divided,” says Joke Aerts of Dutch chocolate company Tony’s Chocolonely.

“A few big companies make huge profits, while millions of small cocoa farmers are underpaid.”

This drives the demand for cheap labor and exploitation.

“It’s been more than 20 years since the big chocolate companies committed to eliminating child labor in cocoa, but not much has changed,” says Ms Aerts. “The prioritization of corporate profits over human rights must stop now.”

Cocoa farmers are also susceptible to changing weather patterns.

According to Fairtrade International, the land suitable for cocoa production will decrease significantly in the near future as a result of climate change.

Experts say that understanding the fermentation process is also vital when it comes to considering the impact of climate change on business.

“[We get] a lot of rain, a lot of humidity. It is not good for the plantations,” says cocoa farmer Carmen Magali Eraso Adarme.

Drying of cocoa beans

The cultivation and processing of cocoa is usually not a very profitable business.

Ms. Adarme’s cacao plantation in Huila, Colombia, is located on extremely steep terrain. Access is difficult and dangerous, especially when carrying heavy bags of beans on their backs.

Ms Adarme is working with Luisa’s Vegan Chocolates and the University of Nottingham on a project that aims to get better taste and better value out of their beans.

Using portable DNA sequencing devices, researchers and farmers can analyze the microbes that ferment Ms. Adarme’s cocoa beans.

With a better understanding of what drives the flavor of premium chocolate, fermentation can be manipulated to enhance flavor.

Ms Vicinanza-Bedi says: “We have used DNA sequencing to confirm exactly what a ‘good flavour’ of a cocoa bean is. Then, using this data, we teach farmers what they can do to maximize their cocoa for the premium market.

Cocoa beans

Improving the taste of beans can increase a farmer’s income

The beans harvested by Ms. Adarme were sent to Luisa’s Vegan Chocolates, where they were made into single-origin bars.

The resulting increase in earnings has enabled Ms. Adarme to send her son to university and learn English. Next, she hopes to improve the transportation part of the business, making her job easier and safer.

Dr David Goupaulchan, an international researcher at the University of Nottingham, says: “Growing cocoa is a very risky business. Yields can vary greatly from year to year depending on weather conditions, pests and disease.”

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Dr. Goupaulchan has been studying the microbes present during fermentation, how the environment affects their growth dynamics, and the role they play in flavor development. His research will be highlighted at the Royal Society Summer Exhibition later this year.

“The fermentation process has a huge impact on the quality and flavor of the cocoa,” he explains. “However, these processes are still very uncontrolled. This results in a large variability in quality between farms.”

A better understanding of the process, he explains, would result in better chocolates for consumers and better prices for farmers.

“My hope is that we can use science to modernize and rejuvenate the cocoa industry and create sustainable livelihoods for all,” he says.

Back in Switzerland, Professor Chetschik aims to get the best out of the raw material, so that after fermentation, the cocoa needs less processing or additives.

“Cocoa is extremely tasty. There are so many active flavor molecules that there is no need to add anything,” he says.

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