Staff Services Student Enterprise

Rheology research proves sweet for multiple industries

melted chocolate
Project contact
Dr Denise Li
Business Development Executive, School of Physics & Astronomy

Research in suspension rheology conducted by the University of Edinburgh has not only helped crack the secret of what makes chocolate so smooth, it is also enhancing sustainability and improving manufacturing processes for a number of global companies across several key industries.

It all started with an initial collaboration between the Edinburgh Complex Fluids Partnership (ECFP), led by Professor Wilson Poon of the University’s School of Physics and Astronomy, and Mars, the global confectionary giant. The project was focused on conching, a critical energy-intensive and time-consuming step in chocolate production.

Developed by Swiss confectioner Rodolphe Lindt in 1879, conching is a process that transforms chocolate from a grainy and unappetising paste to the smooth and desirable product that so many of us love to consume. However, the long mixing time that it requires makes conching a huge energy burden, which can equate to more than half of the energy used by manufacturers to produce chocolate.

Careful rheological measurements found that conching works by breaking down lumps of ingredients into finer grains and reducing friction between particles to produce smooth liquid chocolate. These findings are important as they can enable chocolate manufacturers to improve their processes, potentially reduce the energy required for conching, and help them develop more sustainable forms of manufacturing.

Universal Benefits

Particulate suspensions are ubiquitous across many industrial sectors either as final products or as means to handle particulate intermediaries and waste streams. The work of Professor Poon and his colleagues at the University of Edinburgh, therefore, has the potential to impact a wide cross-section of manufacturing processes. Improvements in such industrial practices can reduce costs and enhance sustainability to the benefit of everyone.

By studying chocolate making, we have been able to gain new insights into the fundamental physics of how complex mixtures flow.

The core findings from our suspension rheology research can be applied to applications across highly diverse sectors of industrial practice, including paints and coatings, energy materials, drilling fluids, ceramics and food products.

This is a great example of how physics can build bridges between disciplines and sectors.

– Professor Wilson Poon

The work in Edinburgh was funded by Mars Chocolate UK and the Engineering and Physical Sciences Research Council.

Header image: dmitr1ch/

Related links

Watch Professor Wilson Poon's chocolate conching seminar

The study, published in Proceedings of the National Academy of Sciences, involved a collaboration with researchers from New York University.

Edinburgh Complex Fluids Partnership website