Stop Putting Airlocks on Your Starters!

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So I can see doing foil on the starter - sounds much easier than the pain I go through to get a rubber stopper to stick in my growler. But, for primaries, I always have to do blowoff, so I will at least need to do that, and then I switch to airlock, but I guess I could switch to foil then.

What about secondary? Why not foil then? Because of the length of time and lack of CO2 output?

I'm planning on doing secondary in corny kegs, so I guess I can just periodically pressure release them and never use airlocks! Will that pressure in the secondary cause the same CO2 backpressure that the foil on primary is trying to avoid in the first place? Seems like if that effect continues in the secondary, it would slow it down.
 
#1 on my list
http://blogs.homebrewtalk.com/olllllo/Full_Disclosure_and_Endorsements/

...here are my Brewing Endorsements.

Now you know where I am coming from:
olllllo...
  1. uses foil to cover his starters;
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Foiling up Coach!

Foilc.jpg
 
fratermus said:
Honest question for those that advocate foil on starters and foil on primary: why would foil allow oxygen exchange in a starter when you want oxygen, and not allow oxygen exhange in a carboy when you do not want oxygen exhange? Are we thinking that the increased volume of C02 production during fermentation makes the difference?




[thinking out loud follows]

I am agnostic about the foil v. airlock issue.

I'll be more convinced when I see experiments that show that foil actually allows significant gas exchange, and the metrics that show how much pressure an airlock provides and to what degree that pressure affects yeast function. I want to see numbers and predictable, repeatable results.

I go back and forth using foil and airlocks on top of stirplated starters and I have noticed no pattern in the results.
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As to the starter... look at the graph posted above... I've seen it before and it's been repeated in many texts. Stirplate + foil(or something to allow some air exchange) is best to get the cell count up.

As far as on the primary goes... it doesn't matter. For the pressure thing, you have two things here. 1 is the pressure is too small to really have an effect. 2nd, pressurized fermentation does retard yeast growth, however it also reduced the amount of higher alcohols produced.(at the expense of damaging yeast cells) The protocol I'm pulling from(Miedaner (1978)) used a positive pressure of roughly 26psi. And you are not touching that with an airlock... or the vessel you are fermenting in.
 
z987k said:
And you are not touching that with an airlock... or the vessel you are fermenting in.
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That is kind of what I am thinking, you guys are over thinking this. Not using an airlock on a starter has many benefits of air exchange, but I am not convinced that foil on the primary has any significant perks. First of all, how much pressure can an airlock really hold in? Second, the beer spends a lot more time in the primary than the starter and you run chances of fruit flies and that working their way in.

There was also talk of letting the carboy sit in a bucket and overflow...just leaving it to sit in it's own filth. This thread went from a very important point and then got taken to just plain unsanitary laziness.
 
Tonedef131 said:
That is kind of what I am thinking, you guys are over thinking this. Not using an airlock on a starter has many benefits of air exchange, but I am not convinced that foil on the primary has any significant perks. First of all, how much pressure can an airlock really hold in? Second, the beer spends a lot more time in the primary than the starter and you run chances of fruit flies and that working their way in.
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I'm only speculating here, but I suppose that at the microscopic level, even the pressure held back by an airlock could have deleterious effects on the yeast. Think how much longer it takes to bottle condition at 68° compared to 70°.

There was also talk of letting the carboy sit in a bucket and overflow...just leaving it to sit in it's own filth. This thread went from a very important point and then got taken to just plain unsanitary laziness.
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How so? What you are describing is open fermentation, employed by many breweries the world over. I've done what you describe as 'plain unsanitary laziness' without a single infection. Once fermentation subsides and the krausen has fallen, I clean up the mess.

It's not lazy, it's about understanding where the genuine risks of infection are and not wringing your hands in fear about the rest.
 
flyangler18 said:
I'm only speculating here, but I suppose that at the microscopic level, even the pressure held back by an airlock could have deleterious effects on the yeast. Think how much longer it takes to bottle condition at 68° compared to 70°.
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The pressure of the beer sitting on top of the yeast cake is way more than the tiny bit of C02 pressure at the top of the fermentation vessel being held back by an ounce of vodka or water.

Did you mention temperature because of pV = nRT? In a bottle there is no exchange of gas, but even in the secondary with an airlock, C02 is dissolving and escaping from the solution in the airlock.

I am a proponent of using foil on a starter, I would think the spinning of the solution will cause a spinning of the air and will slowly bleed out C02 and take in a tiny bit of air.

In the primary it is not much more work to put on an airlock and it bubbling away is indicative of fermentation taking place.
 
The pressure of the beer sitting on top of the yeast cake is way more than the tiny bit of C02 pressure at the top of the fermentation vessel being held back by an ounce of vodka or water.
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Good point. Like I said, I was only spit-balling ideas.

Did you mention temperature because of pV = nRT? In a bottle there is no exchange of gas, but even in the secondary with an airlock, C02 is dissolving and escaping from the solution in the airlock.
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No, I used temperature as an example of how slight changes have large effects on the yeast in response to the statement about the pressure held back by an airlock.

Frankly, I have no reservations about using foil as an airlock. I don't pay attention to bubbles or any of that rot and break out an actual scientific instrument instead of observing a blurping airlock.
 
As for an ounce of water/star-san/vodka/whathaveyou causing a significant back pressure on the fermentation, you're right - it's probably non-existant. However, we have all seen countless pictures and stories from those where the airlock clogged, etc - leading to enough pressure to blow a lid off a bucket. Prior to that blow-off, the CO2 has no where to escape except back into solution, further hindering the yeast activity. From my personal experience, those lids are ass-hard to take off manually, but having enough pressure to force it off? I chalk it up to simply a better be safe than sorry ordeal. I rarely get blow offs, so I personally don't worry about a blow off tube. Those that see constant blow-offs should alter their process accordingly.

Plus, I only have two airlocks and 5 fermenters. The airlocks have been sitting on my sours, so I don't have another option :) I always have foil around...but not airlocks :)
 
Plus, I only have two airlocks and 5 fermenters. The airlocks have been sitting on my sours, so I don't have another option I always have foil around...but not airlocks
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And there you have it. Like just everything about homebrewing, it's about doing what works for you and your conditions. :mug:

And I'll repeat what I said earlier. I quit using the lids on those PITA buckets; a piece of sanitized Plexiglass cut to size is all you need. You can see in if you must, and CO2 can escape.
 
flyangler18 said:
Frankly, I have no reservations about using foil as an airlock. I don't pay attention to bubbles or any of that rot and break out an actual scientific instrument instead of observing a blurping airlock.
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I will occasionally get krausen to the top of my 6.5 gal. carboy which would push the foil right off, that concerns me. That is certainly dependent on the fermentor you use though.

As far as bubbles, I don't think it's rot. Comparing how fast they are coming out compared to how fast they were at peak certainly tells you if fermentation is slowing down. I'd rather not stick any kind of instrument into my wort, scientific or not, until I have an idea that fermentation is about complete. I don't want to sanitize stuff all the time.
 
great thread, i've been reading enthusiastically.

i've always used sanitized aluminum foil on my starters. originally because i was taking advice of more experienced brewers and then because it's what's worked for me.

as for primaries, there are a lot of good arguments for and against here. personally, i've always used airlocks on my primaries and i've never had trouble getting good clean ferments with high attenuation using good temperature control for the mash and fermentation. i've never found it to be a pain to sanitize a stopper and airlock so there isn't much incentive to change for convenience or quality's sake.

i'm afraid i don't really buy the pressure build up argument. the pressure on sumberged yeast from the liquid above them is orders of magnitude greater than the pressure held in by an airlock. i'll accept that dissolved co2 can hinder fermentation but bottle conditioned beers ferment down very dry and again, i've never had problems with underattenuation.

of course, it all boils down to doing what works for you and your system. it's good to know that aluminum foil works for a lot of people and that it should be considered as a viable option. i think that in order for me to change my methods i'd need to be convinced that foil makes better beer, and i haven't quite gotten there yet. but i really enjoy reading people's points of view on the topic and am keeping an open mind about the possibility.
 
This is a great thing I was just thinking this last weekend, you shouldn't really need to use a airlock on your primaries. I'm fermenting a pale ale in a 15 gal food grade plastic barrel right now and I couldn't get it to seal enough to get the airlock to bubble, the whole time I was thinking to myself that it didn't matter but for some reason I wanted to see the bubbles. Now instead of trying to tape the opening so it seals I'll just put tin foil over it!!
 
Figure this would deserve an after action report.


Put the starter together Friday night, using foil instead of an airlock. Activity started within two hours and by Saturday morning, there was an inch of foam on top the liquid and the slurry was thick, vibrant and lovely. I don't even have a stir plate and this starter looked better than anything I've ever done with an airlock in place. 1 pint total volume of slurry, BTW.

Brewed a simple pale ale (OG: 1.055) and pitched the starter at about 11AM on Saturday.

Within 5 hours, the krausen was so active it actually shoved the blowoff tube out of the carboy! Cleaned that and put it back in. By Sunday night, the bubbling had subsided to a pleasant, regular *thup-thup-thup-thup* and it looks like primary fermentation will actually finish very quickly. I'll try to update if anyone cares.


But with this simple change, my starter was thicker and more lively leading to MUCH faster, more efficient fermentation and leading to (I hope) better attenuation and flavor.

*sings* ... now I'm a believer!
 
you guys are putting way to much into this. Simply put you are not going to see any difference with or without an airlock on your primary. There is not enough CO2 pressure. Do you even have a problem with attenuation? What are you trying to fix?

Next say you are fermenting in an hot apartment in the summer, it would probably do you good to be able to pressurize it some. While it inhibits yeast growth, so wait until fermentation is in full swing, it also reduces higher alcohol and ester production... not that anybody has the ability to do this with their fermentation vessels. (wortmonger)
 
And since we're busting myths, how 'bout we finally put this one to rest:

The fermentation vessel should be air-tight (i.e. ale pail).


:D
 
flyangler18 said:
How so? What you are describing is open fermentation, employed by many breweries the world over. I've done what you describe as 'plain unsanitary laziness' without a single infection. Once fermentation subsides and the krausen has fallen, I clean up the mess.

It's not lazy, it's about understanding where the genuine risks of infection are and not wringing your hands in fear about the rest.
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Most modern open fermentation is done in sealed rooms with purified air being pumped through. Either that or is a style of beer which welcomes bugs from the region it is being brewed in. I think that it's a bad practice to allow the fermenter to regurgitate krausen all over itself simply because it is inviting beer bugs to live on and around your fermenter. It is not a guaranteed infection by any means, I have had it happen a couple times to me and I never ended up with contamination in those beers. But like I said, inviting these bugs to live right in the area of your "open fermenter" is not a good thing to get real comfortable with. But you certainly aren't lazy, because cleaning that stuff up after it has crusted on is a lot more work than hooking up a blowoff tube.

It's not that I think open fermentation is bad or that your fermentation even needs to be sealed (I have fermented many batches in a leaky bucket). But I get a lot of fruit flies around during the summer and they would find their way into the beer if I only had foil on. As for me, it's foil (or foam stoppers during fruit fly season) on the starters and airlocks on the primary...at least until I see proof that airlocks are noticeably decreasing the quality of my beers. I don't think not having them around is that great of an excuse either, they are like a dollar and stocked at every homebrew shop on the planet.
 
Sanitary gloves is a favorite of one of my friends.
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Ah...so he prob tapes the all the fingers to the palm...except the middle one...pokes a little hole in the end of the middle one...slaps it on the bung of his carboy...


Add a little CO2 and...:D


For s&g's we do that with some vents at work.:eek:
 
Most modern open fermentation is done in sealed rooms with purified air being pumped through. Either that or is a style of beer which welcomes bugs from the region it is being brewed in. I think that it's a bad practice to allow the fermenter to regurgitate krausen all over itself simply because it is inviting beer bugs to live on and around your fermenter.
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I understand, but I rarely ever have blow-offs with the strains I typically use. If I'm dealing with a strain known for vigorous fermentation, then I use a blowoff. But for the majority of the beers coming out of my brewery, blowoffs simply don't happen. As such, a simple Plexiglass lid is all I need. It allows me to observe the ferment, keeps the bugs out, allows C02 to vent. If I had a problem with fruitflies (which I don't, even in summer), I'd reconsider my regimen.

I think the real trick to successful open fermentation with non-sour beers is pitching large amounts of healthy yeast. I saw quite a few open fermentations when I was in the UK. No sealed air there. Just vigorous healthy yeast.
 
Great Thread here.

I am really interested in this. My last two brews have under attenuated. I thought that I must not have pitched enough yeast, though I used four packets of Notty for a 20-24 gal. batch, so it should have been plenty. I also use medical grade 02, so I know it had plenty of oxygen. AND everything during the brewing itself went fine (good mash temps, gravities, etc.) Also, I have a temp controlled room for fermentation.

Anyway, the design of my blow off tube MAY be causing too much of a CO2 pressure build up, (Per the original comments by Dr. White of White Labs on the first page of this thread) and hindering the performance of the yeast.

Pic below of the top of my fermenter. (More pics of the entire system in my gallery) The opening on the left is a 1.5" tri-clover opening, which I have a 1/2" nipple that fits on it and a long piece of 1/2" hose I use for a blow off. I am sure that it takes quite a bit of pressure to get that tiny diameter hose bubbling in a bucket that is sitting six feet down below the top of the fermenter. (At least based on the violent bubble....then nothing....then violent bubble...then nothing...etc. during fermentation.)

Of course, on the brew that is in there fermenting now, I made a GIANT starter..(two wyeast packets, and over 2.5 gallons of starters to step up)..so, I think I probably had more than enough yeast to compensate for the CO2 pressure. It has been in there two weeks, so I am gonna have to check the gravity and see where this one is

Next time, I am gonna try to use the foil over this little 1.5" opening and see if that helps out.


I have never experienced under attenuated beers before I started using this fermenter (and system). But...that said...my old fermenter had an airlock...

fermenterTop1.jpg
 
RonRock said:
... I DID read that foil was sanitized (well enough) for our purpose's in homebrewing. I did not make that up. But also have my doubts.

I spent way to much time trying to find the reference yesterday and was unable to locate it. But none the less that is what I read. You can't believe everything you read on the Internet I guess.

Thanks
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I remember touring a Reynolds foil factory many years ago.
They start with a huge billet a foot thick and send it through roller after roller until it's thin enough.
Then it's too stiff, so they put it into an annealing oven to soften it.
I'll bet it's sterile when they put it in the box.
After a week in the kitchen?
Who knows.
 
z987k said:
As to the starter... look at the graph posted above... I've seen it before and it's been repeated in many texts. Stirplate + foil(or something to allow some air exchange) is best to get the cell count up.
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I do not doubt the efficacy of a stirplate for getting counts up; I built and use a stirplate. It rocks.

The graph does not address my curiosity, namely the difference in cell counts between stirplate with an airlock v. stirplate with foil.
 
fratermus said:
I do not doubt the efficacy of a stirplate for getting counts up; I built and use a stirplate. It rocks.

The graph does not address my curiosity, namely the difference in cell counts between stirplate with an airlock v. stirplate with foil.
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I agree, I think this is the data we need to determine if foil is useful (at least with stirplates). I predict it won't help any, but I don't have any equipment to do a yeast count.
 
conpewter said:
I predict it won't help any, but I don't have any equipment to do a yeast count.
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I think it would help very slightly, because it keeps everything in suspension to eliminate dead spots. It also constantly knocks CO2 out of solution, so I would guess the overall health of the yeast would be slightly greater, but I don't think the growth would really be effected.
 
Tonedef131 said:
I think it would help very slightly, because it keeps everything in suspension to eliminate dead spots. It also constantly knocks CO2 out of solution, so I would guess the overall health of the yeast would be slightly greater, but I don't think the growth would really be effected.
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Oh I know the stir-plate helps a lot. I've read a couple different papers that say it will give you 2-3 times as much yeast. I was questioning whether foil on top compared to an airlock when used with a stir-plate is really helpful at all. BTW I use foil, but more out of laziness/ease of use than any thoughts about gas exchange.
 
conpewter said:
Oh I know the stir-plate helps a lot. I've read a couple different papers that say it will give you 2-3 times as much yeast. I was questioning whether foil on top compared to an airlock when used with a stir-plate is really helpful at all. BTW I use foil, but more out of laziness/ease of use than any thoughts about gas exchange.
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That is exactly what I was saying. With foil/foam stopper on a stir plate you get excellent yeast growth because they are never starved for oxygen. With an airlock on a stirplate you likely don't get much more growth than you would with and airlock not on a stirplate. The primary advantage of a stirplate is the constant introduction of oxygen, if you put an airlock on but still used a stirplate the only advantage is the aforementioned eliminate dead spots and co2 release. These are helpful in overall yeast health, but have very little effect on yeast growth.
 
sleepystevenson said:
Great Thread here.
Pic below of the top of my fermenter. (More pics of the entire system in my gallery) The opening on the left is a 1.5" tri-clover opening, which I have a 1/2" nipple that fits on it and a long piece of 1/2" hose I use for a blow off. I am sure that it takes quite a bit of pressure to get that tiny diameter hose bubbling in a bucket that is sitting six feet down below the top of the fermenter. (At least based on the violent bubble....then nothing....then violent bubble...then nothing...etc. during fermentation.)
Click to expand...

A 1/2" hose can actually move a good bit of gas without a lot of pressure build up. The pressure won't really start to build up until the hose hits the water level. If you have it submerged a couple inches under the surface of the liquid it won't build up much, if you have it a foot or more under it, it is going to start really putting some back pressure on that hose.
 
PseudoChef said:
Thanks, flyangler!



Damn skippy we do :)

DSC01249.JPG


*Tangent: foil on primary is not just because I'm lazy, but because it allows less pressure forcing back on the yeast. This leads to a healthier fermentation and drives attenuation. Another BN link, but check out the last show from the White Bros. on The Session. If I have some time today, I'll figure out exactly when the topic comes up.

Also, here is a quote from an online chat with Chris White: "On CO2, reckon that a small amount of dissolved CO2 in a fermentation will seriously reduce yeast performance. Even the small partial pressure of CO2 built up under an airlock will have an effect."

and

"I don't like airlocks, I don't think they are needed in primary. I say keep them off and only put on when fermentation starts to slow down. Prior to that, some loose foil is all you need on top....I would not seal the lid, just put loose foil around the sides. You will notice a faster fermentaiton- less CO2 stress."

Source. (Chat Transcripts - Dr. Chris White returns - BrewBoard)

End tangent*
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What do you do with high krausen worts such as hefeweizen? Do you still use the foil, or do you use a blow-off?
 
Saccharomyces said:
Foam control FTW!

I'll never suffer a blowoff again...
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I use it in all my boils. Does it carry over to krausen reduction, or do you add more to the fermenter? I'm brewing my first hefeweizen tomorrow. BTW, the bottle says 2 drops/gallon, but I usually just add two drops when the foam starts to creep up and it completely disappears.
 
brew-skies said:
I use it in all my boils. Does it carry over to krausen reduction, or do you add more to the fermenter? I'm brewing my first hefeweizen tomorrow. BTW, the bottle says 2 drops/gallon, but I usually just add two drops when the foam starts to creep up and it completely disappears.
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It settles out with the break so you have to re-add in the fermenter.
 
I think it boils down to this.
Since I have my airlock and stopper or whatever and it makes no difference whatsoever as to attenuation, yeast character, etc, I'm going to use it. I mean it's right there.... and reusable. And my basement is no where near as clean as well... about anything else.

If you don't want to, go for it, I really don't care what your beer tastes like... (unless I have to judge it) :)
 
Airlocks are a bad thing? I suspect that the American Association of AirLock Manufacturers (AAAM) may disagree.
 
Interesting stuff. Saw a few people talking about using blowoff systems. That's what I do. So, what's the consensus on how to implement this with a blowoff? Have the tubing drop down into an empty bucket? Since microbes can't fly, they can't fly up the tubing, eh? Only thing that could make that happen is a sharp draft, right?

This link provided earlier by someone in this thread makes for a good read. Of specific interest is the bit about Pasteur's experiment with the goose neck tubing with a sterile liquid inside not getting contaminated.

MB Raines, Ph.D. - Guide to Yeast Culturing for Homebrewers - Maltose Falcons Home Brewing Society (Los Angeles Homebrewing)
 

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