Airlock or not?

[grass569]

Hi all

Im new to brewing but have recently brought a starter set from my local homebrew shop, it came with everything i needed except an airlock, but i was told in the shop i didnt need one and tojust put a clean towel over the lid to stop any nasties getting in. Reading around on several websites some people use airlocks some dont. I was told the fermenting process was an aerobic process which (sorry for people who already know) means it needs oxygen to work. whereas wine fermenting is anaerobic so must be sealed. What are your thoughts on this should i lookat buying an airlock or will i be ok. (hope so as ive barreled a milestones lionspride and have today bottled my woodfordes nelsons revenge - just need to wait now aargh)

Thanks in advance

Grass

 

[Dunfie]

Hi G

Beer in the fermenter is most at risk between the point of boiling until the yeast takes control. In the case of a kit it will be between the point you start to open the can and the yeast taking control. There is a couple of points here.

1, All yeast works aerobically until the oxygen is depleted and then it will work on the fermentable sugars anaerobically. We try to ensure that there is a plentiful supply of oxygen in the work before we start the fermentation as this produces the best environment for the yeast to feed and multiply. However once the beer is fermenting you want to avoid introducing more oxygen as it will revert back to the aerobic state and could seriously effect the flavour of the beer through oxidation.

2, Before the yeast takes control you are most at risk of an airbourne bacterial infection. However once the yeast has successfully mades itself at home the wort pH drops to a point where it will be protected from bacterial infection.

So, to your point. I personally don't bother with an airlock but I do place the lid on top to avoid beasties getting it nicking the beer. Once the yeast has taken control and you have nice yeast head on the beer things are usually pretty safe. Even when things slow down and the yeast head drops there is still usually enough of a CO2 cover on the beer to mean things are safe.

I am no expert on the wine front but what I have fermented has done so without creating a protective head so if it was not under an airlock then I would assume that it is more at risk once the initial rapid fermentation has completed and the yeast is beginning to die away. You are probably more at risk of infection or oxidation at that point.

 

[jamesb]

Yeast needs oxygen to reproduce to a decent amount to ferment your beer. After that point it works anaerobically to convert sugars to alcohol and carbon dioxide.

Don't worry about an airlock, but I wouldn't use a towel (although I know people who do).

 

[grass569]

Thanks for the replies. I do have the lid just sat on the top but there are 2 holes in it one for the airlock and anotherr i put in to feed my heater through so the towel was just to stop any dust and bugs gettin in as it is in my garage (the wife hates the smell n wont let me keep it in the house)

 

[warra48]

I don't use a lid or airlock.

My fermenters are covered with cling wrap, held in place with the rubber seal I've eased out of the lid.
The CO2 finds its own way out, and I have the added benefit of seeing what's happening with my brew.

Here's how I do it:

 

[commsbiff]

Hmm... Good idea :thumb: I've been thinking about using cling film and elastic bands on the neck of my pressure barrel so I can use it as a secondary (or just a second - for another brew) fermenter. Hmm... :hmm:

 

[Bribie]

Although some brewers use bucket style fermenters with snap on lids, the the most popular Australian 30 L Fermenter like Warra's is a 'barrel' type with a screw on lid. The lid usually is drilled and has a rubber grommet to take the airlock. Nowadays I usually just pop a (clean) crown seal over the top of the grommet and it works fine.

I do have a smaller 25 litre Fermenter, same shape, for cold conditioning / Lagering and on racking from the 30L primary vessel into the smaller vessel (less headspace which is what I'm looking for) I simply plug the grommet hole with some paper kitchen towel, a bit like a spile in a cask.

 

[Screwy]

Suggest you google or at least read How To Brew online for some FACTS. As some above have pointed out you don't need an airlock, BUT like all things brewing "IT DEPENDS". The lag time before fermentation activity is of concern due to wild yeast/bacterial infection, and during this time precaution should be taken to reduce risk (airlock or a cover of some sort), oxygen in your wort is beneficial to yeast metabolism but this is not drawn from the surrounding air so cover/protect the wort during this time. PRIOR TO FERMENTATION oxygenation can be provided by shaking the wort in the fermenter or by using an aeration stone (sanitised of course) and air pump, or pure oxygen. Once fermentation begins a protective layer of CO2 forms over the beer naturally protecting it (no airlock is required during active fermentation, Co2 production) being heavier than air the Co2 will stay in place unless disturbed by drafts etc. As fermentation finishes and Co2 production is reduced the risk of infection again increases. I fit the fermenter lid and airlock, then remove it once fermentation begins, when fermentation is close to finishing I screw the lid and airlock back on. The reason for doing this is because I prefer to reduce pressure during active fermentation to get the most out of my yeast.

Hope this helps.

Screwy

 

[Bradsbrew]

Screwy when you say you remove the lid, what do you cover with? Or is it open ferment?
Could you not just slightly loosen the lid to relieve the pressure. Or just get rid of the lid seal at the start.
Brad

 

[Screwy]

Screwy when you say you remove the lid, what do you cover with? Or is it open ferment?
Could you not just slightly loosen the lid to relieve the pressure. Or just get rid of the lid seal at the start.
Brad

Spot on Brad, I just loosen the lid when fermenting in the fridge. I prefer to use an old chest freezer, they fill up with Co2, can open ferment (remove the lid altogether) in them as opening doesn't disturb the gas much. Try a flame in the top of your fermenter (match) will go out if Co2 is present, did you do the old pouring CO2 out of the beaker experiment at school. It's lovely stuff for protecting your beer.

Screwy

 

[Druncan]

I use a blow off tube into a platic bottle (1l tonic) with some starsan. I was sick of having to clean the airlocks when the krausen gets too exited. It's a small scale of what many breweries use.

 

[Ghillie]

Simple fact of the matter, get an airlock.

Not using an airlock is a bit like crossing a quiet road without looking. Most days you'll make it, but someday you'll get run over. Brewing consistently good beer is about control and mitigating risk. An airlock is a dirt cheap, straightforward way of mitigating anything wrecking your beer.

A lot of guys use blowoff tubes (it's a Yank thing) but they're quite messy and uneccessry. If you need a blowoff, it's because you're fermenter is too full. Either put less wort in or get a bigger fermenter.

23L batches in a 30L FV and you'll never need a blowoff in a million years.

 

[Zephyr259]

Woah! 9 year old thread necro! How did you stumble into this one @Druncan? An yeah, only time I used a blow-off tube was as Dutto suggests and when I had too much wort in the FV...

 

[DavidDetroit]

it's because you're fermenter is too full. Either put less wort in or get a bigger fermenter.

I also suspect overly large starters.

 

[phillc]

When you're experimenting, mistakes can happen.

I usually brew experimental batches in a 10l fermenter, but only fill with 8l. Almost always this has been fine. However, last weekend I used Nottingham yeast for the first time and pitched at around 30deg C. I had a krausen explosion, something that doesn't happen with s-04 or s-05 yeast.

I usually use an airlock, but had to quickly rig a blow off tube.

 

[DavidDetroit]

As airlocks go, why not? We're talking about reducing oxygen. Covering and uncovering could be a negative. There could be disagreement, but I don't see how reducing oxygen is arguable (specifically after brew day). The whole, sealed bucket or carboy thing is quite logical and requires a minor investment. Covering a container, in any way, not using an airlock isn't necessary--not counting those who are trying to achieve a particular effect. As an aside, I quite enjoyed the "quiet road" example.

After five years, I'm still waiting for anything to come up through the airlock of my plastic FV. I believe my FV is the 6.5 gallon kind. I watch and wait and ferment and never come close to needing a blow-off tube. I brew high ABV (9-12%) beers pretty much exclusively but have done a wide range including Kolsch, wheat and double IPAs.
I'm wondering if it's my use of dry yeast (mostly two packs) that's the reason I never have that issue.

 

[DavidDetroit]

A lot of guys use blowoff tubes (it's a Yank thing)

Is that a derogatory term for someone from the US? I Googled it but it was inconclusive.

 

[Ghillie]

Is that a derogatory term for someone from the US? I Googled it but it was inconclusive.

No not derogatory at all, I certainly hope not - and hope it never came across as such.

Some slang (almost jovial) terminology used over here:

Scottish - Jocks
Welsh - Taffs
Americans - Yanks

If I somehow caused offence I do apologise.

 

[Ghillie]

After five years, I'm still waiting for anything to come up through the airlock of my plastic FV. I believe my FV is the 6.5 gallon kind.

If you're doing 5 gallon batches in a 6.5 gallon FV I would say that's ideal and the reason why you've never had an issue.

Every photo I see online of messy FV's, clogged airlocks and krausen on ceilings is always down to a 5 gallon batch in a 5/5,5 gallon carboy or bucket. It's just illogical.

 

[Godsdog]

Fermented in a bucket and lid with no airlock for 30 odd years and never had a bad brew.last 3/4 years have used the fast ferment and 9 out of 10 can't get a seal to get airlock activity.since reading this thread im tempted to do what warra 48 does and cling film the neck of the fastfermenter with an elastic band to hold it in place.I like that idea and see no problem in getting an infection from doing so