UPDATE 1PM: The ultimate tragedy arising from the deaths of three young friends who drank home made "moonshine" was that it should never have happened at all, a prosecutor has told a Toowoomba court.

In sentencing submissions before Toowoomba Supreme Court, Crown prosecutor David Meredith said had home brew whiskey maker Bill Lynam simply labelled the various containers of ethanol, methanol and other substances he had on his Ballandean property, the incident could have been avoided.

"This whole tragedy just didn't have to happen," he told the court.

After a seven-day trial, a jury found Bill Lynam, 71, guilty of three counts of manslaughter arising from the deaths of his son Joel Lynam, 21, Vincent Summers, 21, and Bryan Wilmot, 30, and causing grievous bodily harm to his other son Joshua Lynam who sustained serious organ failure after the four had drunk methanol laced "bourbon" made up by Bill Lynam for them on June 7, 2013.

By its verdict, the jury had accepted what was the Crown's most likely scenario that Bill Lynam when making up the spirits had instead of using ethanol, which he made from distilling wine, but industrial strength methanol which he bought for making biodiesel for his machinery on the farm.

Few of the plethora of containers and drums on the property had been labelled and the Crown suggested Mr Lynam had retrieved the wrong container before making the brew.

It was not suggested Mr Lynam had done anything to deliberately harm anyone, but that in not taking the proper care he had inadvertently poured the poisonous methanol into a mix with water and bourbon essence to make up the drink instead of using ethanol.

By his actions he had failed in his duty of care to the four young men and was thereby criminally negligent,Mr Meredith said.

Each of the deceased was found to have died from methanol poisoning.

Joshua Lynam, who told police he had only had a small amount of the brew compared to others who drank all of the two-litre bottle, had since made a full recovery.

During Bill Lynam's sentence hearing, a number of victim impacts statements from the families of the deceased were read, each speaking of the ongoing heartache of losing their respective loved one.

Bill Lynam's daughter Wendy Pannach conveyed her family's deep sympathy for the other families, adding her family shared their suffering.

"To the Wilmot and Summers families, we can only say how sorry we are that you have lost your sons, brothers and partners," she said via a prepared statement.

"It's an agony that we know well having suffered the loss of Joel.

"We will remember Joel as a smart and shy young man who had a knack with technology and plenty of unrealised potential."

The court heard Bill Lynam had no previous criminal history at all, was a well respected member of the Ballandean and Granite Belt communities and was known for helping others.

In sentencing him, Justice Ann Lyons said she had to weigh up the seriousness and the consequences of the tragedy with Bill Lynam's otherwise good character and his failing health.

Justice Lyons sentenced him to six years in jail but ordered he be eligible to apply for release on parole after having served 18 months.

11.30AM: Ballandean man William Lynam has been sentenced to six years' jail over the deaths of three men and grievous bodily harm of a fourth after drinking home-brew bourbon.

Justice Ann Lyons, in the Toowoomba Supreme Court this morning, sentenced the 71-year-old to six years jail.

Lynam will be eligible to apply for release on parole after serving 18 months.

11AM: A Ballandean father found guilty on three counts of manslaughter should serve up to seven years in prison with no early release, prosecution in the case has said.

Prosecutor David Meredith is seeking William Lynam, 71, serve five to seven years after a jury yesterday found him guilty of three counts of manslaughter and one of grievous bodily.

Mr Meredith used the Jayant Patel precedent which he told the court was useful as it also involved three manslaughter charges, and one grievous bodily charge.

Mr Meredith submitted Lynam serve five to seven years and recommended against early release due to the matter having gone to trial.

The seven men, five women jury verdict yesterday found Lynam to have been criminally negligent when brewing home-made bourbon which he gave to four men, including his two sons, in June 2013.

Lynam's son Joel, 21, and his two friends Vincent Summers, 21, and Brian Wilmot, 30, died after drinking the home brew at the Lynam property on Puglisi Lane in 2013.

Lynam's lawyer John McInnes is starting his sentencing submissions to the court.

Justice Ann Lyons has this morning heard victim impact statements from the families of Lynam's victims.

The statements spoke of the great loss each family had endured and the profound impact the three men's deaths had on them.