"There is nothing honourable about such a hideous practice or the people who carry it out," he added.
Mr Justice Bean made clear Goren would not be eligible for parole until 2030, when he will be nearly 70.
The court had heard that on 7 January 1999, the part-time fish and chip shop worker, told his son Tuncay to kiss Tulay goodbye at their home in Woodford Green, London, as he would never see his sister again.
Jonathan Laidlaw QC, prosecuting, said he killed Tulay "to restore the so-called honour" of the family, who originate from Turkey.
The term "honour" was an "appalling and inappropriate way" to "dignify" the offence, he added.
The court heard Mr Unal was brought up as a Sunni Muslim while the Gorens were from the Alevi branch of the faith.
Despite coming from places no more than 60 miles apart in Turkey, a relationship between the sects "would not have been tolerated", and Tulay was killed by Goren "to avoid further humiliation".
It is believed Tulay was temporarily buried in this garden
The court was also told Goren served three years in jail for a hatchet attack on Mr Unal, 13 days after the murder.
But the attack and the disappearance were treated separately and it was two months before detectives began to suspect Tulay had been murdered.
Mehmet Goren's wife Hanim, 45, is now living in fear after she named him as their daughter's killer, saying he had "swallowed" Tulay.
He collapsed in the dock at the Old Bailey as she began giving evidence against him and she later screamed at her husband across the courtroom, demanding to know what he had done with the girl.
Police said they were now better able to recognise "tell-tale signs" connected to honour violence.
Jonathan Laidlaw QC, prosecuting, said that the Goren case was a "terrible reminder of what honour-based crime can involve" and a "wake-up call" to the existence of the problem in this country.
Following the verdict, police and lawyers praised Mrs Goren and Tulay's sisters.
Det Ch Insp John MacDonald: 'He has had no remorse whatsoever'
Detective Inspector John Macdonald of the Homicide and Serious Crime Command said: "Although it has taken some time, there has finally been some justice for Tulay."
Tulay's older sister Nuray Guler, 28, has called on her father to tell the family where she was buried.
"For my father, I have only one request. I ask that he finally discloses the whereabouts of my sister," she said.
"I wake up at night wondering where Tulay may be. In quiet moments during the day I ask myself if she suffered or knew what was in store for her."
In a statement read outside court on behalf of Ali Goren, he said: "The case has caused so much suffering for the Goren family."
Cuma Goren also thanked the jury and said he would like to go home to have time to spend with his family.
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