Bill Lynam sat with no outward expression as the jury in his manslaughter trial brought back guilty verdicts to all charges.
Lynam, 71, had pleaded not guilty to three counts of manslaughter arising from the deaths of his son Joel Lynam, 21, Vincent Summers, 21, and Bryan Wilmot, 30.
The three friends had drunk a methanol laced home brewed "bourbon" prepared by Bill Lynam on his Ballandean property on June 7, 2013.
Joel's brother Joshua, the only survivor of the party of four, suffered serious organ failure and the jury found Bill Lynam guilty of grievous bodily harm arising from his injuries.
It was the Crown case that while Bill Lynam had not intended to harm anyone, he had been criminally negligent in not taking sufficient care when making the brew.
Justice Ann Lyons remanded the 71-year-old in custody overnight to appear in the Toowoomba Supreme Court for sentence hearing in the morning.
Outside court, Bryan Wilmot's sister Kylie Williams spoke of the relief felt following the verdict.
"We're grateful for the verdict," she said with obvious emotion.
"We'd like to thank the prosecution, the judge and jury, the Queensland Homicide Support Group and the police involved."
By its verdict, the jury had accepted the Crown case that Bill Lynam had used industrial strength methanol instead of ethanol mixed with water and essence when, upon request of the four young men, he had made up a batch of his home made grappa.
Bill Lynam had for many years used a process of extracting ethanol from wine sourced from wineries in the district to make his home made alcohol.
He drank port made from the process while he produced spirits for other people.
However, he also made bio-diesel on the property for which he bought industrial strength methanol.
He claimed he had made the alcohol from stills and the diesel in separate sheds and it was the Crown case that he had retrieved a container from the wrong shed when he went to make the alcohol for the four victims.
The next morning after drinking two litres of the "bourbon" mixed with soft drink, the four had risen feeling hung over but as the day progressed and the methanol was broken down by their bodies all four became seriously ill.
Joel Lynam died at the house before an ambulance arrived, Bryan Wilmot and Vincent Summers died in hospital in the days after while Joshua Lynam spent four days in intensive care but recovered.
Bill Lynam will be sentenced at 9.30am Wednesday.
4PM: A Supreme Court jury has found Ballandean man Bill Lynam guilty on three counts of manslaughter and one count of grievous bodily harm.
He will be sentenced tomorrow.
10AM: A Supreme Court jury has retired to consider a verdict in a manslaughter trial in Toowoomba.
Justice Ann Lyons spent the court's morning session summing up the evidence heard in six days of testimony in the case against Ballandean man Bill Lynam.
Justice Lyons advised the seven men, five women jury of the relevant issues pertaining to the case in which the Crown claims Mr Lynam was criminally negligent when he gave four men, including his two sons, home brew whiskey at the family's Puglisi Lane propery in 2013.
Three of the men died after drinking the brew while the fourth suffered organ failure.
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