Air lock suck in chilled fermenter

[TrickyDick]

Hello,

Curious what strategies others are using to prevent the problem I describe.

Wort is chilled as cold as your water can get it and it is transferred to fermentor. Ferm temps will be lower after further cooling of vessel (could be in a fridge, jacket, etc). If you seal it airtight, the liquid and air will contract inside and could implode a rigid steel conical I suppose. The solution, to connect to the airlock, is problematic because as it cools it creates a vacuum which sucks the airlock water into the tubing or fully into the tank. If you find this issue, and see the water in the blowoff tube for instance creeping up, just lifting it out of the air lock can also cause the liquid to be sucked straight into the tank, plus air and possible contaminants.

How can this be avoided? Waterless air locks probably won't relieve pressure ultimately, unless you can deliver clean counter-pressure air into the tank, you're in a compromise situation. I saw a post long ago with a double chamber airlock using copper tubing soldered to mason jar lids. Too complicated to describe but you can google double air lock to see what I mean. Presumably there would be a HEPA filter to ensure any air sucked backwards would be "clean". So other than these two ideas, what else?

TD

 

[Scout]

Use vodka in your airlock.

 

[itsnotrequired]

at beginning of fermentation, no worries about sucking air in, yeast needs it anyway. can cover with a loose-fitting sanitized piece of foil, like with a starter flask.

when i cold crash, i switch to s-type air locks on my glass carboys. yeah, a little air gets sucked in but no liquid does.

 

[Sourz4life]

S shaped airlocks with less water in them. Although I use star san for it. It'll allow the airlock to bubble in and out.

 

[TrickyDick]

S shaped air locks for the win! Could it be so simple a solution!!? Feeling deflated now.

Not a fan of the vodka in the airlock trick. Rather use boiled water.

 

[steven_mac]

+1 on the S airlock. All I use now.

 

[bucketnative]

Someone had posted about using a hose-barbed HEPA filter on their fermenter while doing "no chill" brewing.

https://www.amazon.com/dp/B00QXRD3SA/?tag=skimlinks_replacement-20

 

[itsnotrequired]

+1 on the S airlock. All I use now.

i still like to use a three-piece for primary fermentation. every once in a while i will overpitch a starter or over oxygenate and get action through the airlock. so much easier to clean a three piece.

 

[jddevinn]

Positive pressure after the fermentation is done.

 

[TrickyDick]

Someone had posted about using a hose-barbed HEPA filter on their fermenter while doing "no chill" brewing.

https://www.amazon.com/dp/B00QXRD3SA/?tag=skimlinks_replacement-20

But without water, wouldn't that let oxygen in???

TD

 

[TrickyDick]

Positive pressure after the fermentation is done.

How do you accomplish this?

Also, how to prevent the problem I posed, which happens before you even pitch.

TD

 

[jddevinn]

What type of fermenters are you using now tricky? Do you still have the plastic ones or did you switch to stainless?

The blow off tube on my fermenters has about 2-3 ft of height and is a 1/2" tube. During the summer I can only realistically cool wort to about 80-90°F without spending a long time cooling. Dropping from ~90°F to mid-60s I never suck StarSan (from a common 5 gallon bucket or an individual milkjug) more than a foot or two up the tubing. As soon as I pull a clamp to pitch it falls back down. Technically I suppose a tiny bit of air gets in but this is the one place in my process that I do not care.

When its time to either cold crash or dry hop I switch the blow off tube to a CO2 line with a pressure relief valve. Technically I suppose you could attached CO2 set as low as possible and a pressure relieve valve set to ~1psig for the entire fermentation.

 

[bucketnative]

But without water, wouldn't that let oxygen in???

TD

An S-type airlock with water will also let O2 in, but it doesn't really matter pre-fermentation, which is what your original post alluded to (at least I think it reads that way).

 

[ZmannR2]

Letting that small amount of oxygen/star san into your fermenter during cold crashing aint gonna affect anything! There's still so much CO2 in there. Kegging/bottling exposes it to infinitely more oxygen than that ever will. Don't worry about it.

 

[TrickyDick]

What type of fermenters are you using now tricky? Do you still have the plastic ones or did you switch to stainless?

I have two: Blichmann 14 gallon, brewers hardware 15 gallon jacketed. I wrapped a cooling coil around the outside of the Blichmann and wrapped it neoprene foam. Works pretty well for controlling fermentation temps. Not sure I'd attempt any lagers in it.

The blow off tube on my fermenters has about 2-3 ft of height and is a 1/2" tube. During the summer I can only realistically cool wort to about 80-90°F without spending a long time cooling. Dropping from ~90°F to mid-60s I never suck StarSan (from a common 5 gallon bucket or an individual milkjug) more than a foot or two up the tubing. As soon as I pull a clamp to pitch it falls back down. Technically I suppose a tiny bit of air gets in but this is the one place in my process that I do not care.

I use blow off tubes dangling into old PBW jugs filled with some water. My problem with my kolsch sucking water was probably because I chilled to 58 and created more vacuum.

When its time to either cold crash or dry hop I switch the blow off tube to a CO2 line with a pressure relief valve. Technically I suppose you could attached CO2 set as low as possible and a pressure relieve valve set to ~1psig for the entire fermentation.

I the jacketed tank I can inject gas through a port fitted with a diffusion stone. I have a spunding valve at top so I can release the pressure that way. I intend to use as a brite tank. It didn't occur to me to use it for anti-suck until after the fact. I can't easily do this on my Blichmann tank though.

I'm not too savvy at the whole quoting thing as you can see...

TD

 

[jddevinn]

I the jacketed tank I can inject gas through a port fitted with a diffusion stone. I have a spunding valve at top so I can release the pressure that way. I intend to use as a brite tank. It didn't occur to me to use it for anti-suck until after the fact. I can't easily do this on my Blichmann tank though.

I'm not too savvy at the whole quoting thing as you can see...

TD

I would love to use by conicals as brite tanks but the pressure rating on them is basically nothing. To connect to the Blichmann you can use a triclover port. Warning.... links are all over the place

Triclamp to NPT fittings are cheapest here from Bobby https://www.brewhardware.com/category_s/1841.htm

then add either a NPT tee or cross if you want to add a pressure valve. and

NPT to MFL adapter for CO2 in https://www.brewhardware.com/product_p/flarem14xmnpt14.htm

Use this as a blow off, you'll have to mess with it and a pressure gauge to get it set right. https://www.morebeer.com/products/s...KdnrETeb15Y0PQ3KFdpNiVQEco6sqs1JdEaAjNn8P8HAQ

In the end I added the blow off valves for "safety" (I'd have to set something wrong to over pressurize.... but I design vacuum equipment for a living and would never hear the end of it if I broke something by neglecting a $10 saftety valve). I don't worry about the suckback during the cooling phase cause I am normally in the brewery cleaning and can pull the blowoff tube to vent if needed, and this is the only step in the process I don't care about oxidation.

 

[TrickyDick]

Thanks. I have the TC version Blichmann... Which has threaded fittings,so what's the point. I have the TC blowoff adapter too, and they also sell weld less bulkhead TC ports, but I'd need to drill another hole to implement that (in the lid) and not sure I want to. Think that I'll just pop open the pressure release weight to let in air and release the vacuum.

Thanks for the tips!