A faulty fluorescent light fitting has been deemed the most likely cause of a fire which severely damaged an historic Waikato vineyard.
Waikato fire safety investigator Peter Hallett said due to the severity of the damage caused to Vilagrad Winery in the June 29 fire they couldn't be 'conclusive' about the finding, but were confident they had ruled out every other cause.
The fifth generation Nooyen family lost precious family heirlooms and amounts of wine in the blaze which damaged destroyed between 60 and 70 per cent of the near 100-year-old vineyard, set up by Ivan Milicich Snr on the outskirts of Hamilton in 1922.
Mr Hallett said both he and the insurance company's electrical engineer came to their joint conclusion about the fluorescent light fitting as it had been the subject of different fire patterns and damage compared to the other light fittings in the laundry.
He suggested businesses that were concerned about the age or state of their fitting to get them assessed or replaced as newer fluorescent bulbs were made up of different components.
When contacted, winery winemaker Jacob Nooyen was shocked - yet relieved - to hear the cause had finally been determined.
"A faulty light bulb? Wow. A lot of the staff are going to be relieved because of couple of them thought it was going to be their fault and I told them it's not their fault, it's no one's fault. I'll have to ring the whole family now."
One of the morning of the fire, as firefighters continued to dampen down hotspots, Mr Nooyen told the Herald the vineyard would be back up and running by October.
It was a surprise announcement for his family at the time, but he's now stoked that with the help from friends and volunteers, they've been able to fulfil that hope, not only for themselves and their staff, but also customers who had events - including weddings - booked in at the site.
It had been thanks to their help that the site now looked markedly different from the morning of June 29.
"What we got achieved in two days was just unbelievable...the site looks fantastic, it looks amazing."
Temporary kitchen, toilets and wine barrels were now being set up while a marquee was ordered on Thursday.
Their first major event is a wedding on Saturday, October 10, followed by their first official public event, a family fun day and lunch on Sunday, October 11.
The fun day will feature musicians from the album Hamiltune - sale proceeds of which are going towards Vilagrad's re-build - featuring music from not only Mr Nooyen's high school band, Illegal Green, but also other 1980s Hamilton indie rock bands including Knightshade and Devilskin's Paul Martin.
October 31 will see the winery staging its re-opening party, the R18 Summervines Fire Festival featuring The Black Seeds, Tiki Taane, Peacekeepers - which includes P Digsss and Sambora from Shapeshifter - P Money, along with a selection of DJs.
Mr Nooyen had been humbled by the support as most acts were either playing for free or a small fee to help the winery get back on its feet.
"Tiki was one of the first to ring me, that's where the idea stemmed from, he rang me a week after the fire and said 'Jake, anything I can do for you, I want to play for you for free and your family, you've been so good to me in the past' and I was just crying."
The next and final stage will see the new kitchen, laundry, office, barrel and wine shop built on its existing site.