Sucking air through airlock when chilling wort

[FlatStrap]

I always struggle to get the wort below about 22C when chilling using an immersion chiller so will fill the fermentor at that temp, close and put airlock on to chill down to 18 or so in the fridge before pitching yeast. What is the risk of infection from the air coming in through the airlock as the wort chills slowly and creates a vacuum over a few hours? I have done it this way a few times without any significant noticeable effect but wonder when there is the odd off flavour present post fermentation. I always fill the airlock with starsan solution of which a very minor amount bubbles back in and I'm not concerned about that. Will any air passing through the starsan area be sanitised to some extent as it passes through the solution section?

 

[wide eyed and legless]

You are worrying for nothing, instead of using an air lock put a clean tea towel over the top of the fermenter till your ready to pitch.

 

[Spiesy]

Grab yourself a Sterilock. $9, will filter any air coming in.

 

[Grott]

Personally I don't like to wait before pitching the yeast, at 22C I'd pitch and reduce temp over the next few hours. You say you put in the fridge and it only takes a few hours.
Cheers

 

[S.E]

Personally I don't like to wait before pitching the yeast, at 22C I'd pitch and reduce temp over the next few hours. You say you put in the fridge and it only takes a few hours.
Cheers

That’s what I often do pitch around 22c and let it drop to about 17c-18c in the fridge. I don’t use an airlock just place the lid on loosely and quite often take the lid off completely and open ferment once I see the yeast head forming.

Years ago air locks and sealed fermenters were wine makers equipment. Beer was normally fermented in buckets with close fitting lids and most books and instructions advised to remove the lid once fermentation started and put it back on near the end.

I think John Palmer wrote something about not daring to remove the airlock giving the impression the sky would fall down if you did causing undue worry for many new brewers. How To Brew is a great book packed with useful info but there are a couple weird comments in it.

 

[fraser_john]

I use a sterile air filter, from Craftbrewer.

When I sterilize my conical fermenter with steam, it sucks a lot of air back in whilst cooling, same after I drain the chilled wort in, keeps sucking in air. I pitch and leave the sterile air filter in place for a few hours till it reaches equilibrium, then change to an air lock.

 

[S.E]

I always struggle to get the wort below about 22C when chilling using an immersion chiller so will fill the fermentor at that temp, close and put airlock on to chill down to 18 or so in the fridge before pitching yeast. What is the risk of infection from the air coming in through the airlock as the wort chills slowly and creates a vacuum over a few hours? I have done it this way a few times without any significant noticeable effect but wonder when there is the odd off flavour present post fermentation. I always fill the airlock with starsan solution of which a very minor amount bubbles back in and I'm not concerned about that. Will any air passing through the starsan area be sanitised to some extent as it passes through the solution section?

To directly answer your question “What is the risk of infection from the air coming in through the airlock as the wort chills” the risk is so insignificant that I wouldn’t worry about it.

If you are concerned about the “very minor amount bubbles” getting in through your air lock you could use a sterile air filter as suggested.

However as you have also said you use an immersion chiller, fill the fermenter then close and put the airlock on you will have already have exposed the wort to far more unfiltered air than will bubble back through the airlock as it cools.

Do you aerate your wort prior to pitching and if so are you filtering the air or using oxygen? If not this will also be more of a risk than the bubbles getting back through the air lock.

 

[wynnum1]

The yeast takes care of the infections you are the greatest risk for infection the quicker the yeast can work the better.

 

[Liam_snorkel]

Use cling wrap.

 

[Dan Pratt]

Do the sterile air locks need the filter replaced each batch? If not how then how many brews can you use it for?

 

[fraser_john]

Do the sterile air locks need the filter replaced each batch? If not how then how many brews can you use it for?

I have used one for two years straight, I just make sure that between uses, I spray the wort side connector with starsan and cover with foil and spray the tip with starsan. I also use the sterile filter for starting racking processes by connecting the sterile filter between aquarium air pump and the fermenter.

 

[S.E]

I have used one for two years straight, I just make sure that between uses, I spray the wort side connector with starsan and cover with foil and spray the tip with starsan. I also use the sterile filter for starting racking processes by connecting the sterile filter between aquarium air pump and the fermenter.

What’s the advantage of using an aquarium pump for racking mate? Do you mean you blow filtered air into the fermenter while transferring or am I misunderstanding this?

Wouldn’t you just leave the filter in place and let it filter the air coming in to replace the beer?

 

[fraser_john]

What’s the advantage of using an aquarium pump for racking mate? Do you mean you blow filtered air into the fermenter while transferring or am I misunderstanding this?

Wouldn’t you just leave the filter in place and let it filter the air coming in to replace the beer?

I just use the aquarium pump to start the racking process by pressurising the fermenter, once it is flowing, yeah, disconnect air pump and let it suck air through the filter.

 

[mfeighan]

I use a sterile air filter, from Craftbrewer.

When I sterilize my conical fermenter with steam, it sucks a lot of air back in whilst cooling, same after I drain the chilled wort in, keeps sucking in air. I pitch and leave the sterile air filter in place for a few hours till it reaches equilibrium, then change to an air lock.

Im interested, do you have pics of your steam setup?

 

[fraser_john]

Im interested, do you have pics of your steam setup?

This is mine, but anything similar of ebay would work. I also use it for sanitising kegs before filling, all chemical free.