On a winter morning, the temperature is a chilly eight degrees Celsius but inside the International Cocoa Quarantine Centre (ICQC), which simulates tropical conditions, the air is a balmy 23 degrees.
"Cocoa plants are generally quite difficult plants to grow," said Heather Lake, a technician at the newly-revamped centre, which is funded half by the British chocolate industry and half by the US government.
"They don't like too much sunlight, they don't like too much shade. It's quite difficult to get the climate correct," she told AFP at the facility, which is hosted by the University of Reading.
The centre's aim is to reduce the amount of disease affecting cocoa plants by quarantining them before sharing them with different countries to produce new, more resistant varieties.
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The plants are often collected in the wild on expeditions to the tropics on which researchers collect cuttings or seeds from disease-free samples.
At a time when changing tastes in emerging economies like China and India are fuelling global demand for chocolate, the centre acts as a vital resource for producer countries when pests or droughts strike crops.
Cocoa originates from South America but west Africa now dominates production, accounting for 73 per cent of global output, according to the International Cocoa Organization.
Such a heavy concentration of production in one region -- Ivory Coast and Ghana alone represent 60 percent -- makes it vulnerable to shocks.
Prices leapt to almost USD 3,400 (3,000 euros) a tonne in New York in September amid fears that the Ebola crisis in west Africa could affect cocoa supplies.
The three countries worst hit by Ebola -- Sierra Leone, Guinea and Liberia -- represent just 0.7 per cent of world cocoa output and saw their yields plummet.