.. In the never-ending quest to produce great beer, I finally did away with the "shake the carboy" method of oxygenation and got my hands on a diffusion stone, and an O2 regulator. Much thanks to Justin, Jon, Dr. Scott and Jamil for all of the recommendations about this on the show (especially the fermentation show).
- I don't have an inline filter. Is contamination from the mini O2 "welding" canisters a common problem?
- How often to re-oxygenate? The instructions that came with my diffusion stone recommend:
- For 1000ml starter propagation: oxygenating 10 seconds every hour, for 6-8 hours
- For 5 gal wort fermentation: oxygenate 1-2 minutes (depening on original gravity) before pitching, and then once again in 12 hours.
I remember Dr. Scott mentioning something on one of the shows about re-oxygenating at about 1-2 hours after pitching, as well? The more I think about it, it seems that you would want to continue to introduce oxygen into the solution at regular intervals as long as the yeast were still in their aerobic phase. Once the yeast transition into the anaerobic phase, true fermentation and alcohol production has begun and you don't want to introduce any more oxygen into that environment. As homebrewers, how can we tell when the aerobic->anaerobic transition has taken place? Approximately 12 hours after pitching?
