The company expanded from a two-man operation where William and his brother did everything, from the farm work to the laboratory processing, to an operation employing over 70 people. "We worked pretty hard and in the process expanded the property to 30,000 stock units."
William's father was an accomplished mountaineer, chaired the Mt Cook National Park board and was trustee to many high country stations ensuring the family got more than familiar with the South Island's mountains and high country.
That experience he still enjoys today with his own family; wife Marion and their three daughters -- Rachel, Julia and Tessa.
William remembers researchers frequently visiting his grandparents at the station. "It was through this constant exposure to the enquiry and investigation of what is going on and how to make things better which made a big impression on me," he said.
His appetite for all things science is fuelled by reading on the origins and workings of the universe, biology and natural history. He currently serves on the Ministry for Business, Innovation and Employment's Science Board.
One thing is apparent -- he's a proud Timaruvian; His biotech company, South Pacific Sera, recently won the nationwide business video competition for Gigatown, nudging Timaru into second place overall. Not surprisingly he is on the board of Aoraki Development.
Akin to his passion for the mountains, William and Marion are "keen skiers" and still compete in Masters ski racing. "It's a great excuse to go fast on skis," he says with wry smile. He represented New Zealand in the University Winter World Games in Czechoslovakia as an alpine skier.
The 53 year-old is passionate about running, though his favoured distance, the 400m, is no longer on the agenda.
Dr Rolleston's achievements in sport and business suggest he is competitive and analytical. As a keen follower of athletics and rugby, he attended the last London Olympics and the French Rugby World Cup.
"That whole psychology behind sport and all the strategies athletes use to get that vital edge interests me," he said.
And becoming Federated Farmers' president is there any special strategy he has had to learn?
"Bruce (Wills) and I used to talk a lot so we had a pretty good sense of what each other were doing. But I have certainly taken lessons from his leadership and his ability to network and bring people together."
As for goals as president there was naturally focus on evidence and science. The challenges "around water, the environment and water storage are well known".
"If you give farmers' clear evidence of a problem they will get motivated to find a solution. But if there is nothing clear they get frustrated and I think that is where Federated Farmers can act and clear that path with evidence and solutions so farmers can buy into it where necessary and push back where we need to."
Dr Rolleston, meanwhile, does not shy away from controversial subjects like climate change and genetic modification (GM). He was awarded the distinguished Biotechnologist of the year for his advocacy for science in the GM debate.
He says one-dimensional solutions advocated by many environmentalists lack credibility. "The thing is, there is never one solution, people are always looking for the golden bullet and actually that is not what it is about. It's about finding those incremental changes that make the world a better place. Everything you do has consequences.
"These are all tradeoffs. There is no perfect world. If you want to ensure people live better, healthier lives we have to progress otherwise, we go back to the Dark Ages and no one would want to go there," he said.