The skinny on airlocks?

[Coyotey]

I'm losing my mind here trying to find facts about the proper use (or relevance) of airlocks, sealed lids and stirring.

Even though this topic is often brought up, it often ends up with one post saying airlocks and air tight lids is the only way to go - while the next post states the opposite. And so on and so on alterating back and forth without reaching any real consensus.

I'm searching for a consensus because the answer for this must be based on the laws of science where only one answer can be correct? We are after all dealing with fundemental constants.

On the other hand...if we were, say, discussing recipes (where there can be many correct answers and combinations) disagreements lead to creativity and the creation of new tastes.

So first the constants (as I understand them)...and then my questions.

Yeast has to be woken up from a dormant state.
Yeast needs oxygen in order to reproduce before it can process sugar.
Yeast does not particularly like carbon dioxide.
Yeast needs to feed in order to survive.

I've just now finished making a basic 25L cornmeal/sugar mash and have used EC-1118 (2 5g. packs). I also used 4ml. alfa amylase that liquified the mixture nicely. My fermenter is a 50L. bucket with a tight fitting lid and an airlock on top. Keeping it in the basement where it's cool since ec-1118 prefers lower temperatures. So...nothing fancy.

Since yeast needs air to reproduce, is it correct to cut off the flow of oxygen with a lid and an airlock? Am I missing something? Also, before fermentation naturally starts to swirl and mix the wash, should the wash not be regularly stirred to avoid everything settling? Are the "rules" for (for example) wine making so different? Winemakers regularly advocate for giving the wash plenty of oxygen during the first few days of primary fermentation.

I would appreciate for someone to science the hell out of this question for me. There are too many contradicting views out there for a new beginner to digest.

Skål !

[acfixer69]

There a two points to make.
First airlocks and tight seals are not a must have on the fermentation vessel. Most use them to watch rate of co2 being expelled.
Second many just cover with a towel and rope around to hold the critters out.

In both cases the mash/wash should be well aerated prior to pitching the yeast. Stirring after the yeast is not recommended because is can induce unwanted bacteria.

AC

[RedwoodHillBilly]

Bacterial infections aren't always a bad thing. You have to make your own decisions.

[acfixer69]

Bacterial infections aren't always a bad thing. You have to make your own decisions.

That's why I said unwanted bacteria.

AC

[StillerBoy]

+1 to what acfixer stated..

In doing the first stage of fermentation, a seal lid and airlock is not a requirement.. now if you're going to do a secondary fermentation, as in wine making, then you want it to be sealed, as you do not want any oxygen to come in contact with the fermentation.. in making alcohol, we are not doing a secondary fermentation..

Mars

[StillerBoy]

the answer for this must be based on the laws of science where only one answer can be correct?

There is no one answer to your question.. there is multiple ways, and all give a result that is valuable in the process of fermentation..

yeast needs air to reproduce,

Yeast require oxygen to reproduce, not air, that's why a wash/mash needs to be well aerated..

You may want to research yeast behavior in wine/beer making, as it will give a sound base of understand what all happen in the process of fermentation..

Mars

[Kegg_jam]

Jump in and do your own experiments.

I started out paranoid I was going to get an infection if I didn’t use an airlock. Now I only use one when I think it will be sitting around for a while.

[Kareltje]

I'm searching for a consensus because the answer for this must be based on the laws of science where only one answer can be correct? We are after all dealing with fundemental constants.


I would appreciate for someone to science the hell out of this question for me. There are too many contradicting views out there for a new beginner to digest.

Skål !

It is a mistake that only one answer can be correct in science. Several sciences that study the same object can find different answers.

And then there are other worlds.
One can use very different techniques to get the same result.
Then there is difference in taste, which can lead to very different techniques.

When I made wine or beer, I was very strict in hygiene and used an airlock and made sure all utensils were sterile.
Now that I make distillate, I do not care about hygiene so much.
When you read about the muck that goes into thunder, you will not care about hygiene anymore.

And what Kegg_jam says!

[Chixter]

I use airlocks on my small 6 gal fermenters more to fill the hole that the tops have cut into them than any other reason. Oh yea they're fun to watch. In my 20 gal Brute pail fermenters I just cover with the lid to keep out dust and crap like welding splatter, metal chips, etc. that abound in my shop.

[shadylane]

"The skinny on airlocks"
Guess that depends on what your trying to ferment, how much and the environment your doing it in.
Was going to explaining the how, where and why, but I ran out of usable brain cells, before alcohol

[Badmotivator]

I believe the predominant opinion is that airlocks are not important, although in some specific situations they may be indicated. Consider this:
You can pitch as many yeast cells as you like, giving them a billion-fold advantage over stray bacteria. Furthermore the acidity and alcohol are generally inhibitors to many bacteria. Then you are probably going to distill the ferment within days of completion, not bottle it and let it sit and fester like with beer and wine. Lastly, you don't drink the ferment in any form, just the condensed spirit, which can not be infected.

Now if for any reason any of those factors are different, you might want to take extra care with sanitation. But in general, for most ferments, you really don't need to worry very much about sanitation or airlocks. Clean your stuff, sanitize it real quick, and then don't worry.

[Skipper1953]

They were invented to amuse cats and small children.

[Cu29er]

.

Yeast only needs the oxygen introduced while aerating the wort when filling the fermenter. If your mash is thin enough, the yeast's carbon dioxide bubbles will stir the pot.

It's the carbon dioxide layer over the fermentation that resists oxygen loving molds and bacteria -- providing a protective seal for the yeast to continue working without interruption.

An open topped bucket can maintain the protective CO2 layer but it may also allow the merry little breezes to scoop that protection away and give the other critters like fruit flies and their vinegary feets a chance to get started with mischief.
If an ill-fitting lid remains undisturbed on the fermenter until fermentation is complete then all may be ok. Or not. It's a Vegas dice rolling game. The risk is a spoiled batch costing raw ingredients and a week or two of lost fermentation time. A two dollar airlock is pretty cheap insurance to protect how much money you have tied up in sugar, corn, and/or malted grain.

And airlocks are happy little bubbling devices.

.

[Coyotey]

Thanks for all of your input gents! The experiment continues here! I can't help but compare the airlock question to the thermometer-on-a-pot-still debate...."useless as tits on a bull" say the old-timers - "but it gives us something to look at"!

I think the advice about not being too overly paranoid about infections and hygiene is a good one! AND...Again it seems that the old-timers should be listened to: "Don't f*ck with it, just leave the damn thing do its thing, stop fidgeting and find something else to mess with".
Having said that, I run down to the basement every half an hour to f*ck with it

So since there are aparently several correct answers to any given question in science - I'm doing everything wrong or everything right or a combination of the two. In the end it's all the little bubbles that count! Get more experience my son!

It's now been about 24 hours since I pitched the EC-1118 and I'm proud to report that I have seen ONE bubble today. Since it's probably going to turn out that I am indeed doing everything wrong - that little bubble was probably the last dying gasp of a fly that landed in the wash while I was f*cking with it

Happy bubbles guys! Thanks again for contributing to the madness!

Skål!

[fizzix]

It's now been about 24 hours since I pitched the EC-1118 and I'm proud to report that I have seen ONE bubble today. Since it's probably going to turn out that I am indeed doing everything wrong - that little bubble was probably the last dying gasp of a fly that landed in the wash while I was f*cking with it

That's funny!
Which leads into how a loose lid gives you NO bubbler activity on a perfectly happy ferment. Ask me how I know.

[NZChris]

So since there are aparently several correct answers to any given question in science...

If you are more specific with the question, the answers will be more refined. E.g. 'Should I use an airlock on a fermenter of warm molasses wash?' requires a different answer to 'Should I use an airlock on my TPW when I'm not sure when I'm going to be able to distill it?'.

[Coyotey]

So since there are aparently several correct answers to any given question in science...

If you are more specific with the question, the answers will be more refined. E.g. 'Should I use an airlock on a fermenter of warm molasses wash?' requires a different answer to 'Should I use an airlock on my TPW when I'm not sure when I'm going to be able to distill it?'.

I look forward to becoming far better experienced with this great hobby in time which will eventually result in more and more refined queries to those even more experienced than I.

In my round-about way, and for fear of seeming too general, I was trying to be specific by describing the process I am in now by writing the following in my initial post:

"I've just now finished making a basic 25L cornmeal/sugar mash and have used EC-1118 (2 5g. packs). I also used 4ml. alfa amylase that liquified the mixture nicely. My fermenter is a 50L. bucket with a tight fitting lid and an airlock on top. Keeping it in the basement where it's cool since ec-1118 prefers lower temperatures. So...nothing fancy".

I've pretty much recieved an answer for my inquiry, but my point was that many other posts discussing this topic (with equally specific case studies) have resulted in contradicting results - hence my frustration - and the reason for this post.

[DAD300]

If I were doing five gallon buckets in the house, had long or unattended ferments, I might use a tightly sealed airlock to keep the house contaminants out.

I do 200 gallon ferments in a barn. The top has a 26" opening. I use a flat piece of plastic (HDPE) to cover the opening. The ferments make a enough Co2 to keep the top of the ferment covered, effectively sealed. When they finish, they have enough alcohol to prevent infection.

But the size doesn't change a thing. The decision to airlock has more to do with the time you leave them set out.

Lots of huge fermentation are done with nothing on the top, fully exposed to the air. But they finish and go straight to a still within hours, not days.

[aquavita]

MakersMarkFermentationVat

Open Air Fermentation !

On the tour, the guide stuck his hand in and took a taste.... guess not too worried about infection.

[Pikey]

Lol - The answer to your question is of course - Yes !

You can use an airlock, if you want to watch the bubbles and know when it's slowing down

But you don't always see it - Dry corks will let the CO2 through and you'll never see a bubble - same with loosish lids.

As a winemaker I used to have dozens of 'em blurping away.

Then I hadn't got one for a new ferment and used a bit of a plastic bag, held around the neck with an elastic band worked fine and teh CO2 seeped out ok.

Then I used my bigger fermenters, with the lid screwed on and backed off a half turn or so - so they were a bit loose - that works fine too.

aereation - Aquarium air pump and airstone - chucked in there a half hour or so before pitching the yeast (or after if you forgot )That gives the yeast plenty of oxygen for the "Aerobic stage" (Yeast breeding up to viable colony size ) - [SOme chuck in loads of bakers yeast and that wll work too ]

The yeast does NOT need oxygen when it enters the anaerobic stage - that's when it produces alcohol - got that ? Aerobic = yeast breeding - anaerobic = yeast making alcohol !

PS There's far too much empahasis these days on "Consensus" Remember once upon a time there was "consensus" that the world was flat ! Did that make the "Cnsensus correct ?

[Antler24]

I'll add this: I use trash cans to ferment, and don't use airlocks. Once pitching yeast I don't open the cover until I'm ready to run it. I've let washes sit for up to 12 months, never had one sit for less than a month. I have a 12 gallon batch of rum that had a small lacto infection, just one batch. I think it's my best rum to date.