How scientists created a chocolate bar out of thin air

US biotechnology startup Circe Bioscience has created molecules using microbes, including a type of fat that mimics cocoa butter to produce what it calls “the world’s first gas fermentation-based chocolate”.

The fat can also be used in confectionery products such as truffles and has a host of possible applications in the sweet sector. The scientific discovery could potentially address global food supply chain disruptions caused by the 2023-2024 cocoa shortage​ and subsequent cocoa prices that have been travelling on a ‘parabolic’ upward trajectory.

The technology, developed by a research team at the Wyss Institute for Biologically Inspired Engineering at Harvard University, converts greenhouse gases (GHG) such as hydrogen (H2) and carbon dioxide (CO2) into useful products such as fats and oils using microorganisms.

Using microbes to make ingredients

“We use synthetic biology to insert DNA from plants and animals into microbes,” Shannon Nangle, Co-Founder of Circe Bioscience, the startup originating from the Institute explains.

Food grade fats are made using microbial fermentation Image: Getty/Susumu Yoshioka

“We screen these microbes for the highest production, then grow them in fermentors in a process similar to brewing,” says Nangle. The microbes accumulate oil in their cells, which the Circe team then harvest and purify just like plant butters and oils.

The team then remove the microbes. “All that’s left is the oil that is chemically identical to the oils found in nature,” she says. “We can make a variety of different butters and oils, from macadamia oil to specific palm oil fractions and even animal fats,” she says.