airlock curiosity

[themashedone]

Ill start off by saying that i know that to test fermentation use a hydrometer. with that said my question is this some beers ferment without bubbling through the airlock however the two bi products of fermenting are alcohol and CO2. Now in a air tight container with fermentation taking place why dont you see the air bubbles in the airlock. is it because fermentation is happening at such a slow rate that you dont notice the pressure dissipate or what just curious.

 

[g-love]

I would have to say that it depends on the amount of head space in the fermenter, as well as fermentation temp. A lot of head space will just let the CO2 sit on top the liquid without having to vent. Also, there will always be some CO2 being absorbed into solution, the colder the liquid, the more absorption. Combine the two variables and it's possible you don't get airlock activity. But I would also say that with a 5 gallon batch in a standard sized fermenter that is 100% airtight that you are going to see at least some activity

 

[Hammy71]

And if your using a bucket, it's doubtful the lid is really "air-tight".

 

[themashedone]

even so the co2 will take the least path of resistance so its going to leave through the airlock before the lid at least thats my take.

 

[Yooper]

even so the co2 will take the least path of resistance so its going to leave through the airlock before the lid at least thats my take.

That's not been my experience. I've had a few lids that I thought were tight, but I never saw even on bubble out of my airlock.

But if yours always bubbles, that's fine.

 

[Revvy]

We've covered this to death here....Here's the answer I gave last time this came up.

The temptation to rely on the airlock really comes from homebrewing kit instructions and the books that are put out on homebrewing. What I've found from this site is the airlock really is a mediocre indicator of what is going on. Time and letting the yeast do its magic is the key. Rarely does yeast and time not make a powerful combo in this process.

Personally, I'm such a noob I don't even use my hydrometer yet. Just trying to get process down before my head explodes with the science of it! Cheers!

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, atmospherinc changes, slow down in fermentation, the cat hitting it, openning them, bad seals, and yet gravity readings indicate all is well (when you get the scared newbs to ACTUALLY take a reading.)

You start to realise that relying on airlock activity is really flawed. 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?

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...

So that's why it's a good idea NOT to relie on or stress out about what it is or isn't doing.

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 whre a gravity reading indicates that fermentation is happening beautifully.

 

[Sea]

I think th OP was inquiring as to why the airlock would fail to bubble, not why he couldn't use it to gauge fermentation.

The answer is simple, the fermenter's not airtight. If it was truly airtight, then it either bubbles, or you've got no fermentation.

 

[thezepster]

I think th OP was inquiring as to why the airlock would fail to bubble, not why he couldn't use it to gauge fermentation.

The answer is simple, the fermenter's not airtight. If it was truly airtight, then it either bubbles, or you've got no fermentation.

+1

 

[reim0027]

Maybe put a "My airlock isn't bubbling" link in the FAQ sticky?

 

[tvtoms]

I had a brew once that fermented so hard, I could see the lid warping upwards, and the co2 was whistling constantly out of those tiny holes in the airlock lid. I was so worried it would blow off the top, I hung a shower curtain around the whole area to isolate the potential volcano, lol. Turned out fine. No drama. But I'm just saying, be careful what you wish for, hehe.

 

[Revvy]

I had a brew once that fermented so hard, I could see the lid warping upwards, and the co2 was whistling constantly out of those tiny holes in the airlock lid. I was so worried it would blow off the top, I hung a shower curtain around the whole area to isolate the potential volcano, lol. Turned out fine. No drama. But I'm just saying, be careful what you wish for, hehe.

I've blown the lid off two brew buckets, it isn't fun. I just brewed a beer using Burton Ale Yeast. It's a true top cropper, I have a blowoff tube on it and a half gallon jug with starsan in it. I put that on day 2 after finding the airlock full of krausen TWICE. 5 hours after I put the tube on I had over 1 inch of yeast in the bottom of the collection vessel. And after cleaning that out I had more in it the next day.

Every beer is different, and so is every fermentation- that's another thing, it's never a good idea to compare one with the other, and not to assume just because a beer behaves differently than we expect that there is anything wrong. We're dealing with living micro-organism, and they have their own temperments and behaviors. No two ever act totally the same. So it's best to assume the best rather than search for the worst case scenario.

 

[Hockeyhunter99]

OP - i like this question.

is there a beer that, when in an air tight container, would not release CO2 out the airlock??

would like to know the answer.

 

[themashedone]

I was just curious as to what happens to the co2 pressure if not going through airlock I know my beer is fermenting due to my hydrometer readings. Ive just read on here an awful lot of posts saying that airlock wont always bubble during fermentation and logic just didnt quite make sense.

 

[lschiavo]

I think if the vessel is airtight save for the airlock, it would have to bubble. I have been brewing almost two years now and only have seen two ferments not bubble. One a bucket with an obviously bad seal and the other a better bottle with a warped carboy cap.

 

[themashedone]

I can live with that i just didnt know if there was some circumstance or strain of yeast that produced zero to low enough amounts of co2 during fermentation to not build enough psi to vent through the blow off airlock.

 

[Dondlelinger]

The only way it wont bubble is if

1) the bucket is not airtight(if you have threads on fermentor try to tighten it more)
2) the bung/o ring that the airlock sits in is not sealed.
3) Airlock has crack before the fluid chamber.
4) If your wort isn't fermenting.

thats the only way it wont bubble.

I'm happy my coopers fermentor always bubbles...but if it doesn't I just fix it by fixing one of the first 3 things mentioned above.

 

[jsweet]

Some people said that if you had enough headspace you might not get bubbling even if it were airtight. I do not believe this. Well, technically I do, but I think we're talking like half a room full of headspace. The amount of CO2 released, there's just now way that none of it is going to escape any reasonably-sized fermentation vessel.

That said, yeah, apparently lots of people, especially using buckets, don't get airlock activity, even when they think it's airtight. Given that their hydrometer readings indicate a nice active fermentation, the only possibility is that they are wrong and that there is another way for air to escape.

That said, I think there is one valid use for bubbles-as-indicator: If it's bubbling rapidly, you are definitely still in the attenuative phase. The inverse of this is not true: if it's not bubbling rapidly, that says nothing about the fermentation.

 

[Homercidal]

If the fermenter is truly airtight, you will get bubbles. I don't care how much headspace you have, that space is going to be filled with AIR, so it will take very little pressure to push a bit up through the airlock.

If you have a small leak in a bucket, you can start with great action since there is so much CO2 being made that it can't escape out the leak fast enough. But when it slows down, the pressure required to push out of the airlock will not be there, so it might suddenly stop bubbling as the CO2 is now taking the path of least resistance out the leak.

 

[themashedone]

well said folks... good thread