Funny you should mention this.
I normally follow the Q21 jimjam tek pretty much to the letter and I normally get a 1% yield.
Last week I used only vinegar and no water, i then allowed the acidification stage to sit for 2 days before basing. I then allowed the base stage to sit for 2 days before doing my normal 3x1hr limonene pulls followed by a 4th 24hr pull.
I stopped at 4 as the 4th yielded only 100mgs.
This resulted in a 1.5% yield. I was very happy:d
It was the same batch of bark.