Scientists crack cocoa’s consistency conundrum

Can cocoa fermentation be controlled for perfect chocolate flavour? Summary

• Global chocolate market valued at $140.12bn and growing steadily
• Fermented cocoa is key to flavour but often inconsistent in results
• University of Nottingham identified microbes and conditions shaping taste
• Lab-grown microbial mix mimics traditional fermentation with precision
• Research could standardise chocolate quality like beer and cheese making

Chocolate is unquestionably one of the world’s most beloved sweet treats. In fact, it may well take the number one spot - it certainly does with this writer.

It’s a favourite in drinks, snacks, cakes, desserts, and of course confectionery.

And it’s this popularity that has data analysts, Statista, valuing the global chocolate market at $140.12bn (€119.74bn) this year alone. What’s more, that figure is expected to grow at a CAGR of 4.89% over the next five years.

It’s unsurprising then that industry experts and researchers are investing heavily in finding ways to perfect the taste of this popular indulgence.

Enter fermented cocoa.

What is fermented cocoa?

Fermentation of cocoa is not a new process. In fact, it’s been around for thousands of years, and is used by most cocoa producers.

The process involves yeasts, lactic acid bacteria and acetic acid bacteria being added to cocoa beans, in order to break down the surrounding pulp. This procedure develops aroma, flavour profiles, and reduces bitterness.

The problem with fermentation, however, is inconsistency.

It’s tricky, if not impossible, to guarantee the absolute exact flavour every time - a problem for suppliers, manufacturers, and ultimately consumers.

Until now.

Perfect flavour breakthrough

Scientists from the University of Nottingham’s School of Biosciences believe they’ve cracked cocoa’s consistency code.

In a new study, published in Nature Microbiology, researchers pinpoint the key elements that shape chocolate’s taste, during the fermentation of cocoa beans.

These findings could give chocolate makers a reliable way to produce consistently high-quality, richly flavoured chocolate.

The team looked at the way temperature, pH, and microbial communities interact during cocoa bean fermentation, and how these factors influence flavour.

They identified important microbial species and metabolic features linked to fine-flavour chocolate, showing that both abiotic factors (such as temperature and pH) and biotic factors (the microbial communities) serve as strong and consistent predictors of flavour development.

“Fermentation is a natural, microbe-driven process that typically takes place directly on cocoa farms, where harvested beans are piled in boxes, heaps, or baskets,” explains Dr David Gopaulchan, first author on the study. “In these settings, naturally occurring bacteria and fungi from the surrounding environment break down the beans, producing key chemical compounds that underpin chocolate’s final taste and aroma.”

However, this spontaneous fermentation is largely uncontrolled - farmers have little influence over which microbes dominate or how the fermentation process unfolds. As a result fermentation, and therefore flavour and quality of the beans, can vary wildly between harvests, farms, regions, and countries.

The researchers wanted to find out whether this unstable, natural process could be replicated and controlled in the lab.

Working with Colombian farmers during the fermentation process, they identified the factors that influence flavour.

They used this knowledge to create a lab-fermentation process and develop a defined microbial community - a curated mix of bacteria and fungi - capable of replicating the key chemical and sensory outcomes of traditional fermentations. This synthetic community successfully mimicked the dynamics of on-farm fermentations and produced chocolate with the same fine-flavour characteristics.

“The discoveries we have made are really important for helping chocolate producers to be able to consistently maximise their cocoa crops as we have shown they can rely on measurable markers such as specific pH, temperature, and microbial dynamics, to reliably predict and achieve consistent flavour outcomes,” says Dr Gopaulchan.

This research, say the team, signals a shift from spontaneous, uncontrolled fermentations to a standardised, science-driven process.

Just as starter cultures revolutionised beer and cheese production, the researchers believe cocoa fermentation is poised for its own transformation, powered by microbes, guided by data, and tailored for flavour excellence.

“By effectively domesticating the fermentation process, this work lays the foundation for a new era in chocolate production, where defined starter cultures can standardise fermentation, unlock novel flavour possibilities, and elevate chocolate quality on a global scale,” concludes Dr Gopaulchan.

What does this mean for manufacturers?

As the chocolate industry continues to grow, so too does the demand for consistency, quality, and innovation.

With this breakthrough in controlled fermentation, chocolate makers may soon have the tools to deliver reliably a rich flavour, batch after batch.

It’s a bold step forward, blending tradition with technology, and one that could redefine how the world’s favourite treat is made.