- Joined
- Mar 12, 2007
- Messages
- 6,841
- Reaction score
- 857
If your fermentor doesn’t leak and you keep it at a constant temperature, airlock activity absolutely is a sign of fermentation. The term “off-gassing” is sometimes misused. If the temperature of finished beer goes up it will off-gas CO2 through the airlock. Also, thermal expansion will push gasses out of the airlock of finished or unfinished beer. If the temperature remains constant, the CO2 rich and neutral pressure environment in the head space of finished beer will allow it to hold onto the CO2 that is in suspension indefinitely. Under these controlled conditions, if you have airlock activity, you still have fermentation going on (it may be an infection, but still it’s still fermentation. ) The reverse is also true. With no leaks or temperature changes a lack of airlock activity means your yeast is finished or never started to begin with.
Hydrometers are sometimes nothing more than an excuse for us noobs to play with our beer. You really only need three readings. One pre-boil to confirm your mash/lauter efficiency (so that you can make hop adjustments.) Another before fermentation, and the last before bottling to confirm attenuation. If you leave your beer in the primary for a few weeks at the proper temperature and you pitched health yeast in the correct amount into well oxygenated wort, your beer is finished if airlock activity has stopped for several days in a row after that time (run-on sentence, sorry.) Another hydrometer reading should not be necessary (edit: after this one if it determined that your beer was finished . . . but it might be if your beer hasn't fully attenuated.)
Yeah, we've had that stubborn saison, but . . . trust your airlock!
So science people, is this so wrong?
Hydrometers are sometimes nothing more than an excuse for us noobs to play with our beer. You really only need three readings. One pre-boil to confirm your mash/lauter efficiency (so that you can make hop adjustments.) Another before fermentation, and the last before bottling to confirm attenuation. If you leave your beer in the primary for a few weeks at the proper temperature and you pitched health yeast in the correct amount into well oxygenated wort, your beer is finished if airlock activity has stopped for several days in a row after that time (run-on sentence, sorry.) Another hydrometer reading should not be necessary (edit: after this one if it determined that your beer was finished . . . but it might be if your beer hasn't fully attenuated.)
Yeah, we've had that stubborn saison, but . . . trust your airlock!
So science people, is this so wrong?