No airlock activity

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Joe Crook

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Hi all,

A bit of a curious thing. I put on a full grain brew on Sunday which went into the fermenter on Sunday evening. OG 1045, current gravity around 1035 - so far so expected you might think.

However, I'm seeing absolutely NO activity in the airlock. There is a decent head of foam on the top of the wort so I'm confident I've got a good community of yeast in there. And the reduction in the gravity does indicate that fermentation is taking place, but can it possibly be happening without the airlock registering the production of CO2?

I've read that successive readings of the gravity are (of course) far more accurate than airlock activity as a measure of the progress of the fermentation, but is it possible to have NO airlock activity?

I'm certain I've no leaks where the CO2 could be bypassing the airlock. Maybe I'll pitch in another sachet of US-05 just to be sure that it's yeast that had formed the foam.
 
In simple terms, assuming you have a normal plastic FV with lid, you have a leak between the lid and the rim of the vessel itself. It might look sealed but it isn't. It is quite common. If you really want to see your airlock bubbling, remove lid place four strips of cling film over the rim of the FV and replace lid. Your airlock will start to bubble assuming the fermentation is still going Thats what I do at the end of the fermentation so I know when its properly done. And I dont bother to sanitise the film if it comes straight off the roll
 
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I was in the same boat as you just a few weeks ago and like many others before me I asked the same question as you - and I'll share the answer i got:

It's fine, leave it alone, leave the FV for 2-3 weeks and beer will come out of it at the end.

As terrym says, these plastic FV's seem to leak a bit, even though you'd swear blind they're airtight - my first FV was exactly the same (~5-6USGal one that came with a Northern Brewer Block Party kit).

(Curiously I've since bought 2 x 15L ones which seem to seal perfectly so the airlock keeps bubbling.)

If you really want to do something, I'd leave the lid in place but wrap a load of cling film over where the lid joins the FV to seal over any tiny leaks. Or just leave it, it'll be fine.

Good luck,

Matt
 
I would hold back on pitching another packet of yeast because you have no airlock activity, but i do think it is good practice to have spare yeast incase a brew stalls so keep it somewhere like the fridge

As those above have said if your using a plastic bucket type FV then the air has found somewhere to gently escape even if the lid is fully secured down. Nothing to worry about though enough CO2 will be sat above your brew keeping it safe

In all honesty most my brews have little airlock activity, i also started one Sunday and it has already stopped bubbling with the water level slightly higher on the left hand side, by the weekend it will probably be completely level but i will be 100% confident the yeast is still slowly working. If your temperature is good then i would just leave it alone
 
OG 1045, current gravity around 1035
This tells me you have a leak for sure. The leak could be around the rim of the FV or the base of your airlock. With my FV's, sometimes they seal and sometimes they don't, happens more often the older they get... My advice is to do nothing.
 
Thanks everyone for your input.
It seems I've been fooled by some ageing equipment - it's the same fermenter that I've been using for the last 5 years and I've always just screwed the lid down and off we go. This time there appears to have been a leak as all I had to do was remove the lid, remove and reapply the seal, and put it back on tighter (tighter than I normally like) - hey presto - bubbling away like a good one.
I've never seen this before - I wouldn't have believed that (an actually quite strong) fermentation could be going on and a silent leak venting enough CO2 for the airlock to register nothing at all.
Anyway - all is good - so thanks again.
 
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