Do I need an airlock/Why isn't my airlock bubbling

[MyQul]

A common couple of questions on the forum (and cause of some anxiety) by new brewers are, "do I need an airlock" and "why isn't my airlock bubbling". Just to be clear, this isn't intended a a complete guide but an attempt to answer two frequently answered question. So to try to answer them:

Do I need an airlock?

For beer brewing, the short answer is no. I've never used one, the reason being, my first fermenting vessel (FV) was a coopers one and that just had a lid which sat snugly in the FV using a lip on the lid. Nowadays I just spray some star san on some cling film and cover the top with it. This has the added advantage of me being able to look into my FV's to see what's going on anytime I like without the chance of infecting my brew. I've never really understood why the accepted wisdom is to have an airlock on FV's fr beer brewing.

Why isn't my airlock bubbling?

The first question to ask is has fermentation started? You can find out by looking to see if a krausen has formed, or if there's a scummy layer around the edge of the FV a few mm or cm above the height of the wort level. This means means your wort has formed a krausen but it has then it has dropped back into the wort - both good news, your beer has started fermenting.

You can also find out by taking a hydrometer sample and comparing it with your original gravity (OG) sample (you did take an OG sample didn't you?). If your second sample has dropped a few points lower than the OG this also means your brew has started fermenting.

So why isn't my airlock bubbling if my brew has started fermenting?

Unless you have a tight seal with your lid on your FV the C02 can escape via this route. With the lid being the path of least resistance,the C02 won't be escaping through the airlock and therfore your airlock won't be bubbling

 

[simon12]

I see where you are coming from but I would ask why not have an airlock. Its a good way to see whats going on in terms of fermentation and allows the vessel to be completely sealed from any airborne infections, insects climbing in or anything else falling in. Any other system except a pressurised system (maybe with a pressure release valve) doesn't offer the same degree of protection. I know other methods are easily good enough but again why not have an airlock it certainly does no harm. I agree you certainly don't need one and may prefer not to use one.

It a matter of personal choice but I don't think promoting a no airlock policy is helpful to anyone especially when most fermenters are designed to use one.

 

[Niman]

i have 7 or 8 fermenters and bar 1 none where designed to use an airlock...oddly enough the 1 is the least used....

 

[MyQul]

I see where you are coming from but I would ask why not have an airlock. Its a good way to see whats going on in terms of fermentation and allows the vessel to be completely sealed from any airborne infections, insects climbing in or anything else falling in. Any other system except a pressurised system (maybe with a pressure release valve) doesn't offer the same degree of protection. I know other methods are easily good enough but again why not have an airlock it certainly does no harm. I agree you certainly don't need one and may prefer not to use one.

It a matter of personal choice but I don't think promoting a no airlock policy is helpful to anyone especially when most fermenters are designed to use one.

Thanks for your input here and presenting the other side of the coin and the benefits of an airlock

I'm not exactly 'promoting' not having an air lock, just saying you don't necessarily need one. Your right, in that if this was for a more fully rounded guide to airlocks ideally I would have presented the benefits of an airlock too

However, as I have stated at the begining of the post the thread is simply to answer a question that is often asked on the forum rather than being intended as a complete guide.

Edit: I completely agree with you in that to airlock or not to airlock is a matter of personal choice. My intention for this thread is, as these two questions get asked so often, to simply C & P a link to my thread rather than repeatedly typing the same thing out whenever it gets asked. Undoubtedly the next time the Q gets asked my C & P answer will be amongst other forum member's replies, so the asker of the question will be able to decide for themselves whether they use an airlock or not. I haven't intended this thread to be some sort of anti-airlock zealotry

 

[wheazy_joe]

Always good to understand how other brewers operate, personally I've always used an air lock and quite like them. Agree also that it can cause a bit of anxiety if the air lock isn't bubbling, which tends to lead to the lid being opened etc, which isn't helpful at all!

Its always good to let newbies know the options available to them, there's no right or wrong way I guess.

 

[simon12]

Looks like we will have to agree to agree with each other on this one.
Cheers

 

[SANGER_A2]

Thought I'd add my 2 pence! 😀 Like many others I started off with the cheap youngs fermentation vessel with the flimsy lid and it was rubbish, the airlock never bubbled once and the lid came off completely when I did the vigorously fermenting coopers stout. I upgraded to this for £15, which holds an extra five litres so there is more headspace and the lid is really strong and fits perfectly and stays on. My blowoff tube is now happily bubbling away. So the moral of the story is, if you decide you want water in between the outside world and your brew - make sure you have a decent fv! 😇

 

[LarryF]

I've brewed with and airlock and without the airlock, I dropped the grommet into the wort once, numpty that I am. I just folded up some kitchen roll and taped it over the hole in the FV lid and noticed no difference. The only two things I would say is that having a hole in the FV lid for a blow of tube when doing the stouts is a must, either that or keep a mop to hand. Lastly, when sitting on the forum late at night reading away with my FV about three feet away from me, I find the blub...blub from the airlock very reassuring in the background knowing the wee yeasties are working hard at my future drunkenness. I bought one of the quieter airlocks and I'm thinking of changing back to the old figure S ones as it's louder when venting the CO2 I like it that much, I even once had the FV going beside me and the TC going under the kitchen table, a veritable brewing symphony, another bottle or two and I'd have been conducting.

 

[Twostage]

I use an airlock when I can't see in (white plastic FVs) and the lid left loose when I use 2 and 5 litre water bottles. If you judge it just right you can get the lids to lift slightly with CO2 pressure and then click back down. So you get 'tick' instead of 'blub'.

MyQul is correct with his fundamental question - you don't 'need' an airlock.

 

[DrTerror]

I would like to know why ALL FV's are not made out of clear plastic like the Coopers one?,it makes life a whole lot easier to be able to see whats going on,instead of relying on an airlock.(I have both the Coopers FV,and the Youngs FV,Have not used the Youngs yet,might just use it for a bottling barrel).

EDIT

The lid does fit really well on my Youngs FV,(as I just checked it!),so maybe I will use it as a FV after all....

 

[MyQul]

I would like to know why ALL FV's are not made out of clear plastic like the Coopers one?,it makes life a whole lot easier to be able to see whats going on,instead of relying on an airlock.(I have both the Coopers FV,and the Youngs FV,Have not used the Youngs yet,might just use it for a bottling barrel).

EDIT

The lid does fit really well on my Youngs FV,(as I just checked it!),so maybe I will use it as a FV after all....

That type of clear plastic is more expensive? Not sure really.

Despite coming in a starter kit the coopers FV is an excellent design and good quality. Mines scratched to hell, permanently stinks of beer and the bottom third of the inside has taken on a greenish yellow hue - but it just keeps on truckin'
I'd like to buy a replacement but AFAIK you can only get them in the starter kits in the UK

 

[DrTerror]

That type of clear plastic is more expensive? Not sure really.

Despite coming in a starter kit the coopers FV is an excellent design and good quality. Mines scratched to hell, permanently stinks of beer and the bottom third of the inside has taken on a greenish yellow hue - but it just keeps on truckin'
I'd like to buy a replacement but AFAIK you can only get them in the starter kits in the UK

WOW!,I am lucky there!,only just started on mine!.Hopefully I will get as much use from mine,as you have from yours!.

As far as it is cheaper to produce a 'cloudy' barrel than a clear one,Im not too sure....I cannot imagine it would cost much more to make a clear one TBH.

I for one would be happy to pay a bit extra for a clear FV!.

 

[MyQul]

I think I've had that bad boy for 3 years now. I'd be happy to a pay a bit more for a replacement if I could find one

 

[Chippy_Tea]

I have a Richies FV with a hard plastic lid, it doesn't leak even when turned upside down with sanitiser inside, the other one i have has a flimsy lid and leaks like a sieve, you can tell the quality by how hard it is to get the lids off.

 

[Spoon]

I've only got one clear FV and it's made from PET not HDPE. The practical difference being I can dump boiling water in the latter, but PET goes soft at about 65C (try pouring boiling water into a coke bottle).

Which is probably why most cheap FV are made from opaque HDPE, because most kits call for mixing the extract and boiling water in the FV. That and HDPE is cheaper and stronger.

As for the original question, I'm pretty sure the only reason the fermenters in my LHBS have a hole drilled for an airlock is so that the owner can sell airlocks and bungs! I used bucket fermenters for years without an airlock, the seal on the lid doesn't even break, the CO2 just forces it's way out, so it's probably actually better sealed than an airlocked one!

 

[Bar-Steward]

Just a few thoughts for those who do have a cheap fv with a not too tight fitting lid and an airlock.

You could brush a little runny honey around the top of your fv before putting the lid on. Yes this will dry to a sticky mess eventually but it might help improve the seal and is going to be no worse to clean than dried fermentation froth.

As far as the airlock is concerned, if yours is not bubbling then check the liquid level on either side of the u-shaped pipe at the bottom. If the two levels are the same height and you can see foam on your brew and/or the fv lid bulges upwards in a dome shape, then you have a seriously leaky vessel.

If the water is higher in the open end, then at least you have some pressure inside your fv. Often the water level will get to a certain height and then stop, or even go back a fraction every now and then. This is showing you that at that internal pressure, the fermentation gases are finding an easier way out. Remember that the more liquid you have in your airlock, the greater the internal fv pressure needed to force it up the airlock tube, and the more likely the internal pressure will find weaknesses in the lid seals.

On my poorly fitting fv lid, I only fill the airlock with the tiniest amount of water - just enough to fill the little u-shaped bend at the bottom. This ensures that the pressure needed to force the water about 1cm around the pipe is quite low and means the gas can escape that way before it builds up enough to leak out anywhere else.

I always think a regular bubble from an airlock is a nice relaxing sound because I can see and hear that something is happening inside the vessel, so I try to make it happen even with a poorly fitting lid seal.

 

[Chippy_Tea]

I have found placing a weight in the centre of the lid of my cheap FV does the trick.