I've been thinking about this a little lately. The fast fermentation theory is that fermentation can be achieved at higher temps as long as there is a certain amount of air pressure. Maybe I misunderstood that?
If I am pulling on the pressure relieve valve as a test of whether or not fermentation has ended, am I letting off enough pressure that the higher temperatures are a potential problem?
I'm not overly concerned about my temps, I'm at around 68F in my basement for now. Once I get this pilsner out of the fermentation freezer, I can go back to ale temps and really control it around 65F like I'd prefer. But I am curious about the pressure.
Nope your over thinking it. If fermentation is still active it will quickly build up the low pressure the valve holds. If it's done it's done. But again I wouldn't even do it. To test if fermentation is complete you have to pull up on it 5 or more times an hour or so between to tell if it's done. The valve holding pressure slightly carbonates the beer as it ferments. When you release pressure your releasing the headspace pressure, then the co2 in solution slowly releases to the headspace and you do it again and again until the beer is flat and no more pressure releases. Until no more pressure releases after time between pulls you don't really know if it's done.