Scientists grow 100% British chocolate bar for first time since 1932

In 1932, a six-year-old girl received a chocolate bar unlike any other—one made entirely from British ingredients, grown in a glasshouse at Rowntree's factory in York. That girl would become queen, and for nearly a century, she remained the only person on earth to have tasted such a thing. Now, in the summer of 2026, that singular distinction has been broken.

Maha Khan, a master's student at the University of Reading, has made a chocolate bar with cocoa beans grown in Berkshire, in the same county where she was born. She harvested the pods herself, fermented the beans, processed them through the university's food department, and watched the transformation from raw cacao to finished chocolate without ever leaving the region. The bar exists as a limited edition—only six have been made so far—but it represents something larger than a novelty. It is a deliberate statement about fragility, about the systems we depend on, and about what we might lose if we do not act.

The UK chocolate industry is worth £10.4 billion annually and produces some of the world's finest confectionery. Yet it is entirely dependent on cocoa imported from elsewhere. That elsewhere is increasingly unstable. In West Africa and other major cocoa-growing regions, temperatures are climbing and rainfall patterns are becoming erratic. Crops are failing. Prices are rising. The plants themselves are struggling to survive in conditions they have never known.

Khan described the experience of following the entire process from pod to bar. The raw cacao beans, she explained, are wrapped in a white flesh that tastes like lychee—something most people in Britain never get to experience. The finished chocolate carries the complexity of over 300 cocoa varieties, all grown at Reading's international cocoa quarantine centre. That centre is not a curiosity. It handles 97 percent of the world's international cocoa plant movements and preserves more than 300 distinct plant types, many of which may hold genetic traits that could help cocoa survive in a hotter, more volatile climate.

Khan spoke of the work with a clarity that suggested she understood what was at stake. "This British bar of chocolate highlights the precarious nature of our food supplies," she said. Cocoa plants are sensitive to temperature and rainfall. Climate change is already causing problems. Protecting different varieties is vital if farmers are to have hardier plants that can cope with what is coming. The chocolate, she added, is delicious—rich and complex—but it is also a message.

The university created the bar to mark its own centenary, but the deeper purpose is to draw attention to the work of preserving cocoa diversity. As climate breakdown accelerates, as pests and diseases spread into new regions, the genetic variation stored at Reading may become essential. A single cocoa pod takes six months to grow. Production cannot be rushed. But the need is urgent.

Khan has suggested giving one of the six bars to the Princess of Wales. The symmetry is deliberate: the last all-British chocolate was eaten by a future queen in 1932. The next one, she hopes, will be eaten by another. Both were born in Reading. Both carry the weight of a moment in history—one at the beginning of a long reign, one at the threshold of an uncertain future.