"I still have our house Bomber Blend from Flight Coffee but I've added a single origin menu with something new at least every two weeks.
"This is for people who want some variety. It's like wines and whiskeys - where the coffee is grown, how it's harvested, the climate and soil acidity all affect the flavour. I'm getting coffee from coffee-producing nations like Colombia, Guatemala, Ethiopia, Rwanda and Burundi, all through Flight Coffee in Wellington."
Mr Harris also offers manual brew filter coffee, another single origin option, and says some of the coffee is quite rare. Cold brew coffee is also on the menu.
"I'm committed to coffee with a view so even when this area was closed by flooding, I set up near Bates St. The reason for the cart [rather than a building in town] was so I could provide coffee with a view.
"I have tables where people can sit and just chill out, and during summer there are sewn-up coffee bags to sit on. In the longer term I'd like to convert a vintage bus so people could sit inside or outside to look at the view.
"I'm always tweaking things as I go along but providing single origin coffee was always a big plan. I'm trying to provide a fuller coffee experience in Whanganui."
A long-time coffee enthusiast (when he worked in sales he used to go home twice a day during his breaks to brew his own coffee), he says he has become more passionate about coffee over the years and it has snowballed since starting the business.
There are more plans for expansion though Mr Harris is keeping those under his hat. However, one goal is to serve coffee in real cups instead of disposal cups. In keeping with his interest in recycling and sustainability, he offers keepcups for sale.
In the short term, he will continue to work on building his client base as well as looking after the preferences of his expanding group of regulars.
"If you're interested in what you're doing, people are more supportive and you give a fuller experience for customers."