Briony was sent home from the Bake Off tent after "probably" mixing up salt and sugar in an emotional semi-final.
The 33-year-old revealed she broke the news of what went wrong on a WhatsApp group for the show's bakers.
The one-time star baker was undone by patisserie week and became tearful after her failed showstopper but said she was proud to have made it to week nine.
Kim-Joy, Rahul and Ruby will take part in an evenly matched final, with each of the contestants having two star baker awards to their name.
Briony said: "The bakers were asking on WhatsApp what had happened and I messaged them saying that I was leaving but as one happy semi-finalist.
"I had a little cry after the showstopper but it was more of a release of emotion. I really did leave with a big smile on my face."
Briony was dependant on a good bake for the showstopper but her efforts were deemed "raw" and "very salty".
Judges and contestant were agreed she had probably mixed up salt and sugar in her final challenge.
The glazing in her technical challenge, a Seven Veils Cake, was described by Paul Hollywood as "like incontinence pants", although it was Rahul who came bottom of the group.
Prue Leith said the self-effacing baker had "gone backwards" in patisserie week after being one of the standout contestants in previous challenges.
It was Ruby who was crowned star baker for the second time.
She impressed in all three challenges, while Kim-Joy was praised by the judges for her consistency.
Briony did not do enough to keep her on the show in the final challenge and presenter Sandi Toksvig told her: "It doesn't help if you get your salt and your sugar mixed up."
The baker from Bristol was still delighted to have made it to the semi-final of the show.
She said: "I don't often say that I am proud of myself - but I am proud of myself.
"You really do make friends for life with the bakers as the experience is so unique, it's an unbreakable bond that isn't going to go away.
"I will treasure every moment of my time in the tent and, aside from having my daughter Nora, it's been one of the best experiences of my life."
The Bake Off champion will be crowned after the final on Tuesday October 30.