The six judges were a selection of coffee experts from around the country. Each drink needed at least a "two sip" taste.
"We end up with some very wired sensory judges by the end of the three days," Mr Tadman said.
He said judging criteria was "purely down to taste".
Seventeen-year-old Carla Clendon won the trainee round on Sunday and had come along on Monday to witness the experts in action.
She had become interested in coffee-making through a barista course at her school, Excellere College, had then gone on to do work experience at Columbus Coffee and was keen to pursue a career in hospitality.
Northland Hospitality owner Max Hutchings said his company had hosted the event for the past 13 years as a way of lifting the region's coffee culture.
He said a top-of-the-line machine for a busy cafe could cost up to $15,000, though most cafes had their machines on a lease basis.