Originally Posted by mmb
To me, that would be an equipment fault and I'd strive to fix it. I've never had a batch ferment where there wasn't airlock activity. If the airlock wasn't bubbling, it wasn't doing the job of letting pressure out without letting outside air in.
You know your equipment. The n00b that says it's not bubbling might not know how to use the equipment and saying "It's alright, sometimes it doesn't bubble" doesn't help them use the equipment the right way. You might have a leak in bucket/lid/stopper/whatever that you are aware of. The n00b doesn't know that.
Not had your morning coffee yet?
As I mentioned before, there has been no visible airlock activity (or none within any timeframe I have observed) over the past 6 days now. The krausen fell completely 4 days ago, however, in that same amount of time my Oktoberfest has gone from 1.026 to a now 1.020.
I am not stating this in Revvy's defense specifically but adding my experience (though I admit it is not extensive) and observation to this debate. There is nothing wrong with the equipment I am using, it is in perfect condition. I will concede that it is very possible that the fermentation is so slow that the space of time in which i observed my airlock was insufficient enough (and I have stared a good long time) to see the activity that is actually taking place. However, as I am unwilling to waste more time staring at the airlock when it takes less time to gather a hydrometer reading, the more efficienct and active choice is clear.
There is no reason why a brewer cannot make perfectly good beer by never using a hydrometer. However, when it comes down to it, speculation and/or intuition are not worthy sciences. This is the Science forum afterall. Airlock activity can give you quality information indeed. Airlocks are trusty tools of the brewing trade, they were just never designed to measure the completeness of fermentation. So relying completely on such a device to gather that information is not going to give one consistent results.
The right tool for the job is most often the best tool for the job. I've seen statues carved with a chainsaw that are cool as hell, but I am unlikely to hear about those in the same conversation as those at the Brancacci Chapel in Santa Maria del Carmine in Florence.