Scientists craft UK-only chocolate bar from Reading cocoa in push to spotlight climate risks

A postgraduate researcher has produced the first chocola…

A postgraduate researcher has produced the first chocolate bar made entirely from British-grown ingredients since 1932, a feat that underscores the growing threat climate change poses to cocoa cultivation worldwide.

The creation marks a revival of a treat so rare that, until now, the only person known to have tasted a fully UK-sourced chocolate bar was the late Queen Elizabeth II, who received one as a six-year-old in 1932 from the confectioner Rowntree’s.

That original bar was made using cocoa harvested from a plant nurtured in a glasshouse at Rowntree’s headquarters in York, a remarkable achievement for its time. Now, a master’s student at the University of Reading has repeated the process, growing cocoa plants in controlled conditions and transforming the beans into a finished bar with no imported ingredients.

The project was driven by a desire to

The project was driven by a desire to highlight how shifting weather patterns, rising temperatures, and more erratic rainfall are endangering cocoa production in traditional growing regions, particularly in West Africa, which supplies most of the world’s chocolate. By proving that the crop can be cultivated in an entirely new climate, the researchers aim to spark conversation about adaptation and resilience in the industry.

While the new bar is not for sale, its creators hope it will serve as a tangible reminder of the delicate balance behind every chocolate product—and the urgent need for innovation as the planet warms.

The breakthrough also offers a glimpse into a future where chocolate production could become more localised, reducing supply chain vulnerabilities and carbon footprints, even as the classic taste remains familiar to consumers.