Very cool. I have always admired the pure and clean beauty of blowoff yeast.
Is that your experience?... that it is trubless and cleaner than the cake at the bottom of your primary fermentor?
What is the advantage of capturing blowoff yeast?
Best I can tell, the yeast from the blowoff is a bit like top cropping. Having said that, when top cropping you skim off the "dirty yeast" and protein material early in fermentation and discard it. I don't do this with my setup, although I suppose I could switch out the blowoff bottles after a the first few hours of fermentation. The yeast is cleaner in my experience but you CAN get good results by simply rinsing the yeast cake from the fermenter. I do like the simplicity of just pulling my blowoff bottle off of the fermenter and throwing it in the fridge. My primary goal however is not for an easier yeast recovery but to recover all of that good yeast I was losing to the blowoff. Sometimes I ended up with less than half of the yeast cake in the fermenter. When I used the blowoff, I usually had enough slurry to direct pitch without need for a starter.
I can't say for certain what the protein material does to future fermentations. I haven't had any trouble to date but I haven't gone more than 3 generations with any successive batch. Others may be able to chime in with a more informed opinion. The one thing I do to try to minimize any unwanted portion of the yeast is to swirl up my sample prior to pitching into a new batch pitch all but the last few ml's in my best effort to leave the dead yeast in the bottle.