JAKARTA — The tea industry has watched in envy as coffee’s cachet has skyrocketed across Asia, and now it wants a piece of the action. But it faces a difficult challenge: How to convince people that something they’ve been quaffing like water all their lives can be a premium product. Eliawati Erly, vice president of David Roy Indonesia, the local distributor for Sri Lankan brand Dilmah Tea, recognizes that developing a culture of cool around tea won’t be easy. “People are accustomed to having tea and teh botol (bottled tea drinks sold in shops) since they are young,” she said. Erly and others in the tea industry are well-aware of how coffee companies have benefited from promoting the ethical sourcing of beans and the distinct qualities of single-origin roasts from specific regions.