Suckback during cooling

[guypettigrew]

It's now possible for me to cool my beers after primary fermentation has finished. But there's a problem.

I use a blow off tube which is great when the fermentation is a bit vigorous and the krausen is too much for the FV.

When the beer cools it contracts, or at least the air space above it does. This creates a negative pressure and sucks back some of the water from the container which the end of the blow off tube is submerged in. Not a good idea!

I've now fitted a non-return valve on the end of the blow off tube as an interim solution. This won't stop negative pressure in the FV, but will stop anything being sucked back into it.

How do people who crash cool deal with this? It doesn't seem right to loosen the lid of the FV and let air in after having carefully excluded it during primary fermentation. Or perhaps it doesn't matter? The beer will come into contact with air when it's kegged anyway.

Advice, please!

Thanks.

Guy

[b2b]

I had same problem. When I switch off the heating to cool, I also remove the blow off tube, and replace with an airlock with minimal water in it. When it sucks back, it just bubbles the "wrong" way.

[Fil]

or just crack the fv lid till target temp is reached, O2 at this stage of the process isnt a bad thing its a positive thing and helps the yeast population grow.

[guypettigrew]

or just crack the fv lid till target temp is reached, O2 at this stage of the process isnt a bad thing its a positive thing and helps the yeast population grow.

Oh. I thought oxygen was just good before fermentation. My cooling problem with the suckback is after primary fermentation.

If oxygen is good all the way through fermentation, should the lid of the FV be left open all the time?

Guy

[IPA]

Ferment with lid off after the krausen has formed like this. That will prevent any overspill.



When the active fermentation abates throw away your airlock and replace it with a breathable foam stopper then refit the lid. That will allow two way breathing and keep out any nasties.

Foam stoppers can be found here
http://www.northernbrewer.com/shop/foam-stopper-46-50mm
They are also available in England

[guypettigrew]

Thanks IPA. Wonderful idea. Except tracking down foam stoppers isn't easy. The airlock hole is only about 18mm diameter. There don't seem to be any foam stoppers this small. Perhaps cutting down a larger one is the way to do it.

Guy

[Fil]

Oh. I thought oxygen was just good before fermentation. My cooling problem with the suckback is after primary fermentation.

If oxygen is good all the way through fermentation, should the lid of the FV be left open all the time?

Guy

WHOOPS!! MY BAD NOT READING STRINGENTLY ENOUGH!!
So its the crash cooling when this is ocouring dbl whoops!!
However post fermentation your beer will protected with a heavy co2 blanket created during the fermentation, and will keep the O" off anyway, I use fermentors with screw on lids and simply unscrew so there is free passage of air into the fv its not rushing in its a gentle process as the beer chills so no real worries..

[Piscator]

Oh. I thought oxygen was just good before fermentation. My cooling problem with the suckback is after primary fermentation.

If oxygen is good all the way through fermentation, should the lid of the FV be left open all the time?

Guy

WHOOPS!! MY BAD NOT READING STRINGENTLY ENOUGH!!
So its the crash cooling when this is ocouring dbl whoops!!
However post fermentation your beer will protected with a heavy co2 blanket created during the fermentation, and will keep the O" off anyway, I use fermentors with screw on lids and simply unscrew so there is free passage of air into the fv its not rushing in its a gentle process as the beer chills so no real worries..

There is so much active yeast in the fermenter that the tiny little bit of atmospheric oxygen around the lid is insignificant - you need to remember beer was (and still is) fermented in open vessels for hundreds of years with no ill effects. You would really have to go some to introduce oxygen into a fermenter at levels significant enough to be detrimental to the fermentation, simply exposing the top of the fermenter to air will not have any ill effect.
Cheers
Steve