Wasnt Vances experiment done with the toothpick method? A microscopic amount of oil in 5 gallons?
From someone at New Belgium. in the original post
For the volume of wort we normally ferment, we would pitch about 4500L of yeast, and to that we would add around 300mL of olive oil. To translate that into a 5 gallon size, you would need to measure about 0.0000833mL of olive oil.
OK they were using 1mg/25 billion cells. Mr Malty says 5 gallons of 1.057 wort should be pitched with 198 billion cells. So thats 7.92 mg. Oleic acid is .895 g/mL so thats .0088 mL, about a fifth of a drop.
Somewhere in the thread, somebody calculated .083 mL. I checked it and it seemed right at the time. I dont remember how it was figured.
Looking at it another way, 2100hL is about 11000 five gal batches. 300ml/11000 is .027 mL, half a drop. Still in the ballpark. About a hundred times closer than someone at New Belgium.
From the original thesis:
as the amount of olive oil was increased with each trial, the fermentation performance improved. It is possible that the rate of fermentation and the ratio of esters to higher alcohols could be improved if the amount of olive oil addition were increased beyond the rate of 1 mg / 25 billion cells. For this brand, the increase in total esters was perceived as preferable by the flavor panel.
So, more is better, at least up to a point. And, if you read the thesis youll find that they added it to the yeast five hours before the pitch.