It's one thing to dry coffee to just the right moisture level, but the real difficulty comes in maintaining that level during storage, especially in a hot and high-humidity climate.

The Jamaican Coffee Industry Board, a Kingston, Jamaica-based agency overseeing quality standards for the country's coffee, has begun a series of indoor environment trials focused on coffee storage facilities throughout the island. The board will study the impact of indoor climate on the quality of Jamaican coffee, notably Jamaica Blue Mountain Coffee, one of the world's most recognized and sought after coffee brands.

“Jamaican coffee beans are dried to an ideal moisture level of about 12 percent, and the storage environment needs to be stable in order to maintain that moisture level,” says Gail Nelson of the board's research office. “Ideally, warehouse temperatures should be somewhere between -6 and -3.9oF [20 and 25oC] and relative humidity in the 60 to 70 percemt range.”

The problem, however, is that some of the facilities may not be environmentally stable for storing the valuable beans due to lack of environmental controls and the type of building-construction materials used.

“We want to compare different warehouse conditions and find out how those conditions may be affecting moisture levels,” Nelson says. “If the beans are losing too much moisture, there can be a negative impact on flavor and quality.”

Using Hobo dataloggers from Onset Computer Corp., Bourne, Mass., temperature and relative humidity are being recorded in eight locations across the island. Measurements are taken every 15 to 30 min. Nelson periodically downloads the data onto a PC, using accompanying software, to compare time-stamped graphs of each warehouse to see how climate fluctuates.

“From these trials, we hope to be able to make some conclusions over time about the overall storage conditions of each facility and take corrective action if necessary, such as sealing off roofs or installing better environmental controls,” she says.