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Old 11-03-2009, 02:49 PM   #1
neumann
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Default Explain this to me...

First off, I mean no disrespect to any of the seasoned veterans of brewing on this board. I still hold the consensus of this board way over anything someone at my LHBS or just walking down the street has to tell me. My confusion (at least today's) comes from the whole airlock bubbling (or lack thereof) not being a sign of fermentation. Here is how I understand it: CO2 is a byproduct of fermentation and if you know you have an air tight seal on your fermenter (I understand that the buckets aren't usually airtight but Better Bottles and glass carboys ought to be) where is that CO2 going? I still get that the most accurate way to judge fermentation is via gravity readings. I'm just a little perplexed...

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Old 11-03-2009, 02:54 PM   #2
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It is leaking out, because people make mistakes, or have a lack of attention to detail, or there is no liquid in the airlock

You CAN expect to see bubbles, but since there are factors that will allow pressure to escape by other means, the ONLY SURE way to tell if it is fermenting is with a gravity reading, because that is absolute.

This being said, in 5 years, mine have all bubbled.

Bubbling airlocks are not direclty tied to fermentation, only a drop in SG is.

Airlocks will also bubble if there is no fermentation taking place... they will also go in REVERSE evn if there is fermentation taking place. SG is the only indicator.

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Old 11-03-2009, 02:59 PM   #3
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Queue Revvy's entrance music...

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Old 11-03-2009, 03:00 PM   #4
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Haha, he was the one I expected to hear from first.

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Old 11-03-2009, 03:00 PM   #5
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My airlock never bubbles. Never, never ever. The CO2 is finding it's way out of my primary (I always use the same one) so I get no bubbles. My beer does just fine though.

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Old 11-03-2009, 03:01 PM   #6
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It is an indication not hard evidence. At the end of the cycle the expelling of CO2 can be so minimal that you miss it when you look for airlock activity and consider it done when it is not. I like Revvy's point that it a pressure release valve and nothing else.
I think the deal is that so many people do not know that their vessel is airtight save for the airlock so they get themselves worked up when they don't see bubbles.
Often fermentation is not signalled as soon as I expect it but I can tell if the yeast is beginning to work simply by the changes in the top of the beer. Soon after the bubbling commences.
A butter knife is not a screwdriver.

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Old 11-03-2009, 03:04 PM   #7
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Quote:
Originally Posted by northernlad View Post
A butter knife is not a screwdriver.
But it will work in a pinch...
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Old 11-03-2009, 03:08 PM   #8
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To add to this, and I was rofl when I read the Revvy rant on airlocks and fermentation. I must say that I did also learn something so it was helpful.
For purposes of discussion, couldn't the amount of co2 being produced by the yeast actually not exerting enough pressure to create bubbles, just maintaining pressure? I likened this to my experience when using a blowoff tube in a glass carboy(I agree that it could be leaking from around the tube int he carboy.

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Old 11-03-2009, 03:10 PM   #9
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Quote:
Originally Posted by neumann View Post
But it will work in a pinch...
The fact remains that fermentation is not complete until your Specific Gravity reaches it's terminal point. This being accomplished once all fermentable sugars have been consumed by your yeast. The argument here on these forums relative to airlock activity is not that it is not a sign of fermentation, it is that airlock activity should not be your primary indicator, particularly for determining completion of fermentation. Use the "right" tool for the job, a hydrometer.
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Old 11-03-2009, 03:11 PM   #10
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Or a refractometer (less beer waste)

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