Unilever tea plantation workers' housing amidst the lush, rolling tea fields in the Kericho district, Kenya. (From the book What I Eat: Around the World in 80 Diets.) The Kericho district in the Great Rift Valley has rich volcanic soil, cool air, and a moist tropical climate that's perfect for growing tea. With its popular tea brand Lipton, Unilever has helped make Kenya the number one exporter of black tea in the world. Since the evergreen tea bushes are picked every 14 to 17 days year-round, there is constant work for pickers. They're paid by the kilo of tea leaves and a field foreman reported that they can earn between $3 and $9 (USD) per day. To compete with Unilever and James Finlay, another huge corporate tea producer in Kenya, the Kenya Tea Development Agency represents half a million small-scale tea growers throughout Kenya.