From the Lab:
We’ve had so many questions from commercial and homebrewers alike, about whether adding olive oil to wort can take the place of oxygenation/aeration. We’ve read the New Belgium study, but we decided to find out for ourselves, on a 5 gallon scale. We know that yeast need lipids to build new cells and promote a good fermentation. We also know that they need oxygen (in the range of 8-10ppm) as building blocks for this, but the theory is – what if we provide the lipids themselves?
I did two sets of trials, to get some repeatable (hopefully) data. I brewed two 20-gallon batches of English IPA and split each batch into 4 fermentors. One fermentor was dosed with 5ppm oxygen and one with 10ppm oxygen. Then I used olive oil to one fermentor and a product called Pactoferm (from Birko) in the fourth, an anti-foam product that is made with canola oil. Since I had calculated the olive oil needed for one fermentor to be the equivalent of a drop, I used New Belgium’s method to ensure the addition went smoothly. I emulsified the oil in some 200proof ethanol, then added that to a yeast slurry on a stir plate for four hours. To keep the experiment controlled, I put the other 3 yeast slurries on a stir-plate as well. If you’ve been to the tasting room, tried the beers, and looked at the data, you’ll see that all the fermentations were very closely matched, even the one with lower oxygen.
I think what will be more interesting to see, and a new trial will be done, is how these methods affect later generations – second and third generation fermentations. I think we’ll see more variation. So for the next one, I’ll do several brews. I’d also like to implement a method for the olive oil introduction that someone without an outfitted lab would use. If you’ve done it before, I’m interested to see how you did it! Send any emails to firstname.lastname@example.org.