It;s very interesting to note the various comments on both this subject and the pressure fermenting topics that purport to be based on some knowledge base.
- Don't exceed 10-15psi pressure when fermenting otherwise the yeast will/may die.
- Bottles filled from your pressure fermented beer will not store well
- Filling bottles with a counter pressure filler with beer fermented under pressure isn't a real good idea you should depressurize the fermenter and bottle then add back some sort of fermentable for carbonation.
I regularly bottle from my WW and use a counter pressure set up to do it and those beers/bottles keep well for up to 12 weeks (longest I have kept any pale ales) I bottle at 1.5bar (21PSI) and use CO2 to vent the bottle and bring it up to equal or just below the pressure in the WW
There may or may not be a lot of published data on the subject of fermenting under pressure but in any event those that are doing or considering doing it could do a lot worse than down load the Williamswarn owners manual from their site and take on board how they recommend you ferment under pressure, temperatures and time etc.
For example they recommend 1.5bar (21psi) and 4 days at 23C for ales and then cold crash and clarify. For lagers they recommend 1.5bar (21psi) for 3 days at 15C and then raise the temperature to 18C for another three days before cold crashing and clarifying.
There are many on this site that bagged the Williamswarn as being overpriced etc etc but the fact remains that their processes and procedures work and will also work for any pressure fermenting be it in a Fermentasaurus, a keg or any other vessel that will safely withstand upto 3bar (42psi) pressure
Wobbly