Home Brew Forums > Home Brewing Beer > Beginners Beer Brewing Forum > When To Remove Blow Off Tube & Use Airlock
Reply
 
Thread Tools
Old 11-02-2009, 02:42 PM   #1
Montanaandy
Feedback Score: 0 reviews
Recipes 
 
Join Date: Oct 2009
Location: Montana
Posts: 1,016
Liked 19 Times on 14 Posts
Likes Given: 77

Default When To Remove Blow Off Tube & Use Airlock

I have a batch of steam beer that I brewed yesterday and all appears to be going well. Used the 6.5 gal glass carboy (1st time) to primary this batch. Nice head of foam forming the top of which has risen to about 3" or so from the bottom of the carboy neck. I can see that CO2 from the 6.5 gal glass carboy is bubbling into the 1 gal milk jug with sanitizer at the other end.

My question is this - it has been about 17 hours since the brew concluded so am I safe to assume that the time for a major blow off has passed? Can I now switch to the airlock at this point or should I continue to use the blow off tube and if so, for how much longer? Thanks, Montanaandy


Montanaandy is offline
 
Reply With Quote
Old 11-02-2009, 02:47 PM   #2
Yooper
Ale's What Cures You!
HBT_ADMIN.png
Feedback Score: 0 reviews
 
Yooper's Avatar
Recipes 
 
Join Date: Jun 2006
Location: UP of Michigan
Posts: 65,929
Liked 6209 Times on 4422 Posts
Likes Given: 1656

Default

Quote:
Originally Posted by Montanaandy View Post
I have a batch of steam beer that I brewed yesterday and all appears to be going well. Used the 6.5 gal glass carboy (1st time) to primary this batch. Nice head of foam forming the top of which has risen to about 3" or so from the bottom of the carboy neck. I can see that CO2 from the 6.5 gal glass carboy is bubbling into the 1 gal milk jug with sanitizer at the other end.

My question is this - it has been about 17 hours since the brew concluded so am I safe to assume that the time for a major blow off has passed? Can I now switch to the airlock at this point or should I continue to use the blow off tube and if so, for how much longer? Thanks, Montanaandy
If the krausen has dropped, and it's quiet, you can switch to an airlock if you want. You can continue to keep the blow off on if you want, though. Really, a blow off tube is just a giant airlock.

I never use a blow off tube, but it's because I ferment in 7.5 gallon buckets. If you have enough headspace you don't need one, but if you're concerned that you may have some blow-off, it's better to be safe than sorry! Usually, the most vigorous part of fermentation ends in 3-5 days.


__________________
Broken Leg Brewery
Giving beer a leg to stand on since 2006

Follow me on facebook: https://www.facebook.com/lorena.t.evans
But I'm pretty boring so don't expect much!
https://www.facebook.com/lorena.t.evans
Yooper is offline
 
Reply With Quote
Old 11-02-2009, 02:48 PM   #3
TipsyDragon
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2009
Location: California
Posts: 2,607
Liked 22 Times on 20 Posts

Default

yes you are way safe by now. a blow off tube is really only needed for over active fermentation. typically if the fermentation blows off the airlock or pushes itself up into and out of the airlock then i switch to a blow off till it subsides. then switch back to the airlock when it calms down. but if like you say the fermentation has passed it should be safe to witch to an airlock.
TipsyDragon is offline
 
Reply With Quote
Old 11-02-2009, 02:58 PM   #4
TimWeber
Feedback Score: 0 reviews
Recipes 
 
Join Date: Oct 2009
Location: Pennsylvania
Posts: 160
Liked 3 Times on 2 Posts

Default

I think you're fine to use an airlock. I almost never use blow off tubes, only on beers with really high OGs, some strains of yeast, or stouts. I use 6.5 gallon carboys. Normally you'll know its gonna blow within the first 24 hours. If the krousen is about 2'' thick and holding I'd say swap it out.

Also with the couple of batches that did blow, maybe about 5, I had no contamination and they tasted great. With all that yeast activity it's a bit hard for anything to take hold in your beer.
__________________
Pilot Brewing System


Fermentation Chamber


My carboy washer


You can follow me on Twitter @TimWeber
TimWeber is offline
 
Reply With Quote
Old 11-02-2009, 03:15 PM   #5
BioBeing
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jan 2009
Location: Memphis, TN
Posts: 1,519
Liked 8 Times on 7 Posts

Default

The way you say "nice head of foam forming on top", and the fact that it has only been 17 hours, makes me think that the most active part of the fermentation is still to come. I remember watching one inch its way up the glass, until it started coming out after about 36 hours. If the foam is still rising, leave the blow off on. Unless you have some pressing need to take it off, I'd leave it on until you are SURE the chance of a blow off has passed.
BioBeing is offline
 
Reply With Quote
Old 11-02-2009, 03:49 PM   #6
triangulum33
Whenever it feels right!
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
triangulum33's Avatar
Recipes 
 
Join Date: Oct 2009
Location: NorCal
Posts: 680
Liked 19 Times on 14 Posts
Likes Given: 2

Default

Is there a reason to switch back to the airlock? Space?
__________________

“Always do sober what you said you'd do drunk. That will teach you to keep your mouth shut.”
― Ernest Hemingway



Meine Keezer
triangulum33 is offline
 
Reply With Quote
Old 11-02-2009, 04:02 PM   #7
shortyjacobs
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2009
Location: Twin Cities, MN
Posts: 2,512
Liked 32 Times on 32 Posts
Likes Given: 3

Default

I had a porter that I started last Sunday. I kept a close eye on it for 48 hours, and it seemed to have leveled off in its fermentation, (about 2 inches krausen). I figured I was safe.

It blew off a day and a half later, gunk everywhere....

Now it's blow off tubes until the krausen falls.

The only reason I switch to airlocks is to be able to move the carboys easier.
shortyjacobs is offline
 
Reply With Quote
Old 11-02-2009, 04:23 PM   #8
atromic
Feedback Score: 0 reviews
Recipes 
 
Join Date: Sep 2009
Location: Vermont
Posts: 120
Default

Definitely keep the blowoff on until you see the krausen fall. I had an irish red blow off on me the other day after 48 hours of active fermentation.

It was my first blow off and it managed to make quite a mess in the few minutes it was blowing off before I was able to get the tube attached. I can't imagine how bad it would have been if it had been going all night before I noticed it.
atromic is offline
 
Reply With Quote
Old 11-02-2009, 06:48 PM   #9
Montanaandy
Feedback Score: 0 reviews
Recipes 
 
Join Date: Oct 2009
Location: Montana
Posts: 1,016
Liked 19 Times on 14 Posts
Likes Given: 77

Default

Had trouble posting to this thread earlier but here it goes...

I returned this afternoon and the krausen has increased quite a bit and I can see residue on the blow off tube near the neck of the carboy. 1 gal jug partially filled with sanitizer is bubbling along pretty good. I think that the blow off tube will remain in for the time being given all of the activity.

Re: switching to the airlock from the blow off tube - I just assumed that the airlock with the stopper placed into the top of the carboy afforded a bit of a tighter seal than sticking one end of the 1" tubing down the neck of the carboy and the other into a 1 gal milk jug. I will say though that the seal at both ends seems pretty tight given the activity going on.

This reminds me of another question I had related to the blow off tube - how far down into the carboy to insert it. Right now I have it where there are 2"" extending into the carboy below the base of the neck of the bottle. Is this sufficient? Thanks, Montanaandy
Montanaandy is offline
 
Reply With Quote
Old 11-02-2009, 07:30 PM   #10
BioBeing
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jan 2009
Location: Memphis, TN
Posts: 1,519
Liked 8 Times on 7 Posts

Default

Quote:
Originally Posted by Montanaandy View Post
Had trouble posting to this thread earlier but here it goes...

I returned this afternoon and the krausen has increased quite a bit and I can see residue on the blow off tube near the neck of the carboy. 1 gal jug partially filled with sanitizer is bubbling along pretty good. I think that the blow off tube will remain in for the time being given all of the activity.

Re: switching to the airlock from the blow off tube - I just assumed that the airlock with the stopper placed into the top of the carboy afforded a bit of a tighter seal than sticking one end of the 1" tubing down the neck of the carboy and the other into a 1 gal milk jug. I will say though that the seal at both ends seems pretty tight given the activity going on.
A blow off tube into liquid is essentially identical to an airlock. The only potential problem with a blowoff tube into a pot of liquid is that, if the carboy cools significantly post-fermentation, it could suck liquid back into the vessel. This could happen with a one piece air-lock, but not a 3 piece.

Quote:
This reminds me of another question I had related to the blow off tube - how far down into the carboy to insert it. Right now I have it where there are 2"" extending into the carboy below the base of the neck of the bottle. Is this sufficient? Thanks, Montanaandy
Doesn't matter. Just stick it in till it holds. I put a piece of tubing over the middle stalk of my 3-piece, so it is barely down into the vessel at all. [If you do this, make sure to cut off the cross piece on the bottom of the air lock.] All you are doing is giving the thick krausen an escape route that doesn't involve explosively removing a clogged airlock.


BioBeing is offline
 
Reply With Quote
Reply


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
3 piece airlock or blow off tube richbrostrom Beginners Beer Brewing Forum 7 03-28-2009 06:07 AM
moving from an Airlock to a Blow-Off tube? Dizavin Beginners Beer Brewing Forum 3 02-18-2009 10:06 PM
Remove siphon tube from CO2 tank? sjwelna Bottling/Kegging 6 01-25-2009 01:32 AM
Do I need a blow-off tube / airlock on my fermenting bucket? Danek Beginners Beer Brewing Forum 9 09-15-2007 01:43 AM
blow off tube ok to replace airlock?? Grüner Brauer Beginners Beer Brewing Forum 2 01-28-2007 12:43 PM


Forum Jump

Newest Threads

LATEST SPONSOR DEALS