Tea producers in Malaysia have also been hit by the drought. At the Boh Plantations in the Cameron Highlands, February's crop was down 50 percent.

Caroline Russell, CEO of Boh's Cameron Highlands, says there's evidence to suggest weather patterns are becoming more volatile. "In the dry periods, we would see crop yields fall but the concern in very wet periods is that we would see slope instability because we are growing tea on quite steep terrain."

She believes agricultural over-development in the Cameron Highlands could also have a lasting impact on the flavor of Boh Tea. "There's been a lot of land clearance for agriculture.

"This undoubtedly is impacting temperatures. Ultimately one could anticipate that your flavors would be impacted," she said.

But as consumption increasingly shifts to instant tea and tea mixes at the expense of traditional brews, such subtle changes in flavor are becoming less obvious. "Consumer lifestyles are changing so much that people don't have the same downtime. So, quite a lot of the growth areas in the tea market are in arenas of convenience," Russell said.