Lol. Ive only had 2 batches ferment out with no aIrlock action, but 2 is more than none.
THAT'S THE POINT RIGHT THERE!!!! If it's failed once that's enough to consider it unreliable,
regardless of why it's not happening.
My belief is that 1 occurrance is an anamoly, 2 may be a coincidence, BUT 3 or more occurance is an epidemic...and that's the case for folks relying on airlocks all the time, to me if 1 brewer comes on saying his airlock is not bubbling, AND he takes a reading and finds fermentation is going fine, that's an anamoly...
But DAILY on here there are at least 10 threads stating the exact thing...so MAYBE there is something to this idea that airlocks can be faulty. AND if they have the potential to be faulty, then how can we trust them to tell us what's going on?
You can quibble about it all you want, or deal in semantics, but we deal in sheer volume of users on here, and daily we have airlocks not bubbling, and many of them where a gravity reading indicates that fermentation is happening beautifully.
I've said it over and over and trolls like to try to get me, or even accuse me of lying (which I don't get why I would lie about something like this) but over the years of LOTS of batches of ALL SIZES and BOTH carboys and buckets, better bottles or glass, carboy caps or bungs, new buckets old buckets, s-types and 3 piece, I get about 50% airlock failure rate (but 100% success rate of fermentation) and it's any number if things, usually simply a non tight seal in the bucket or carboy or grommet....but to me the reason doesn't matter....the point is just trying to glance at an airlock and know what the beer is doing, just is NOT accurate.
Besides airlocks tell you the WHAT is happening, that co2 is or isn't getting out of the fermenter....but they aren't telling you the WHY. If it's fermenting or not, or off gassing or not. If it's done or not....
And yes, in an IDEAL situation (like let's say fermenting in a keg with a tight seal and no leak from around the airlock) the airlock SHOULD bubble 100% of the time (providing there's not too much headspace.) If more co2 is created than can be contained in the spave of the fermenter, THEN an airlock should bubble....because an airlock is a valve.
But MOST of us don't have IDEAL situations, and rarely is a plastic or glass fermenter airtight- it really isn't supposed to be anyway...SO we aren't in the best situation to have IDEAL 100% accuracy of an airlock...
And that's primarily because "back in the day" they were heavy and made of glass, and sat fairly tightly on the fermenters. And they were usually s-type, which tend to bubble more easily since they don't have a stupid little center piece to try to lift. So they simply worked better.
But like any POS cheap thing made offshore and of plastic- they don't always work as they should.
Add to the fact that folks who wrote most books are just repeating 30 year old info written by papazian who were writing in the era of glass, they just keep repeating the whole thing rote...even though Most authors and experienced brewers nowadays probably do what a lot of us do and pitch and walk away, not paying attention to anything but a hydro reading (if they feel they need one.)
But they've really failed to let their work- their books or even kit instructions reflect the truth....That most of them don't work too well these days.
Hell I betch papzian still has his glass airlocks from the 70's and prolly hasn't noticed that the plastic ones don't work too well.
And it wasn't really until you get to places like this, websites where you literally recieve hundreds if not thousand of posts a week,,,hundreds a day that you start to spot all these folks whose airlocks aren't or are bubbling or stopping or starting for whatever reason, yeast lag, atmospheric changes, slow down in fermentation, the cat hitting it, opening them, bad seals, and yet gravity readings indicate all is well (when you get the scared newbs to ACTUALLY take a reading.)
So that's why it's a good idea NOT to relie on or stress out about what it is or isn't doing. Just realize that airlocks bubble or they don't, they start, they stop, they bubble fast, they bubble slow, and they bubble or don't whether fermentation happens or not.