I just listed to the fermentor BS show and would like to loose a few comments.
I don’t buy the argument that a corny keg is not suitable for a good primary fermentation because it is tall and slim. To my knowledge, yeast flavor profile has more to do with fermentor height and convection currents than the actual height/diameter ratio of the fermentor. And the few additional inches that the wort will stand higher in a corny keg than in a carboy shouldn’t make a big difference. There should also be similar wort current patterns in a corny keg compared to a carboy. And since it is round there are no dead corners either. You mentioned that none of you compared fermenting in a corny to fermenting in a carboy, for example, and I haven’t either. But talking about it leads to speculation which just creates myths that perpetuate from there.
Another thing that I believe is a myth is the idea that the water column in the airlock makes a difference to the yeast by means of exerting pressure. If you do the math, a 2 cm water column exerts a pressure of 0.002 bar which is 0.03 psi. This equals an elevation difference of about 25m or 70ft. If such pressure differences would matter Denver brewers should make dramatically different beers compared to L.A. brewers.
If there is a difference between open and air-locked fermentation, it must be something else. The presence of oxygen in the head space for example would be a better explanation.
Aside from that it was a good show. Keep the good stuff coming.
Kai