Unlocking aroma: Barry Callebaut borrows Belgian beer techniques to control cocoa fermentation

The company has completed a three-year project in partnership with the Flanders Institute for Biotechnology (VIB) and KU Leuven (University of Leuven) to improve cocoa fermentation with a special yeast that tailors flavour to customer requirements.

‘Tastier chocolate’​

Teams from VIB and KU Leuven   - led by professor Kevin Verstrepen  - visited Barry Callebaut sites in Africa and Asia-Pacific to test various yeasts. Verstrepen claims they have found the ideal strain - Saccharomyces cerevisiae, the yeast used to brew beer.

“When this ‘new yeast’ is added while the cocoa is fermented in the bush, the process becomes faster ​and more consistent. Moreover, the new yeast strain produces more desirable aroma compounds and hampers the growth of unwanted yeast. The result is even tastier chocolate​,” he said.

Barry Callebaut is not yet using the latest controlled fermentation for commercial products, but had been using a separate controlled fermentation technique using microorganisms for its premium chocolate range Terra Cacao.

Farm level fermentation​

Fermentation usually takes place at farm level. Cacao beans are typically heaped into a pile, covered by banana leaves and left to rest for seven days to develop flavor.

Some companies collect cocoa beans to ferment themselves, but Barry Callebaut under its previous fermentation technique kept the process at farm level.

Last year, Nicholas Camu, group manager of Barry Callebaut’s sustainable sourcing program Cocoa Horizons, told ConfectioneryNews​​ that his company had been using starter cultures for the past five years.

Farmer premiums​

Barry Callebaut began with 150 farmers – now over 8,000 farmers in the Côte d’Ivoire take part, each receiving a €60 ($81) per metric ton premium for using the cultures.

The company started by buying 150 MT of cacao beans grown with controlled fermentation. In 2013, that figure rose to 8,000 MT. But controlled fermentation still accounts for only a minuscule amount of the company's 920,000 MT annual cocoa volumes.

The project was supported by the Agency for Innovation by Science and Technology-Flanders.

Nestlé-backed research​​ recently explored the key role acetic acid bacteria plays in cocoa fermentation.  The study by Saarland University said better understanding of acetate formation could help identify the best starter cultures for flavor development.