Zenith International chairman Richard Hall has expressed skepticism over RTD coffee's credentials as the 'next big thing', despite impressive growth since 2003. Speaking at the recent Innobev Global Soft Drinks Congress, in Lisbon, Hall spoke of growth in the RTD coffee category, which Zenith predicts will hit 4.3bn liters by 2018, with 34% growth between 2003 and 2018.