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Old 01-12-2007, 03:31 PM   #1
Dec 2006
Baraboo, Wisconsin
Posts: 8

I'm starting a weizen beer this weekend and I'm using liquid yeast (Wyeast #3068). Some of the reviews I read on this beer said to use a blow off tube. I'm using a bucket as my fermentor and the hole for a airlock is around 1/2" to 3/4". So It looks like I could use a 1/4" or maybe 1/2" tube for a blow off. Is this going to be ok to use a tube this small?
First brew:German weiss
Second brew Vanilla Weizen

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Old 01-12-2007, 03:55 PM   #2
Rook's Avatar
Jan 2007
Bothell, WA
Posts: 381
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I think that most recommendations for blowoff tubes are becuase when you ferment 5 gallons in a 5gal carboy, you need a lot of room for the stuff that comes off the top of the brew, forget what its called (k something?) If you're fermenting in a pale, then you probably have enough room to just put an airlock on there without needing a blowoff tube.

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Old 01-12-2007, 04:01 PM   #3
trinitone's Avatar
Sep 2006
Philadelphia, PA
Posts: 417

Today the letter "K" is brought to you by krausen....

A blow off tube is typically 1" or larger in diameter and as Rook pointed out is generally only needed if you don't have adequate headspace in your fermenter. If you're worried about it then just use the largest tube you can and keep an eye on it.
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Old 01-12-2007, 04:04 PM   #4
Fiery Sword
Fiery Sword's Avatar
Oct 2006
Revere, MA, Massachusetts
Posts: 908
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Originally Posted by trinitone
A blow off tube is typically 1" or larger in diameter and as Rook pointed out is generally only needed if you don't have adequate headspace in your fermenter.
I use a blow off tube so I can drink the resulting KrausenAde out of the jar. mmmmmmm blow off water.....

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Old 01-12-2007, 04:07 PM   #5
RoaringBrewer's Avatar
Oct 2006
Lancaster County, PA
Posts: 1,787
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Yeah, the "Ale Pail" type fermenter or a 6.5g glass carboy should have plenty of head-space for a 5 gallon recipe in 95% of cases. There are times (like pitching directly onto a yeastcake, etc.) that you will get blowoff out the airlock or it will clog the airlock and blow the entire lid off (can you say mess?) or blow out the airlock (hopefully you don't clog an airlock on a carboy and explode the glass carboy, ouch!)...

I wouldn't say this is 'rare' b/c I've seen several people describe this occurrence on these very boards (including an exploding glass carboy), however 19 of 20 5 gallon recipes should ferment fine in the Ale Pail or 6.5g glass fermenter.

You definitely should use a blow off tube as an airlock on any smaller fermenter (5.5 gal capacity with a 5 gal recipe for example)... If you do use a blow-off tube as an airlock, I'd suggest getting 3/4" - 1" tube as the smaller ones will clog and could cause the same problems noted above if the tube doesnt blow out of the hole...

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Old 01-12-2007, 04:10 PM   #6
Blender's Avatar
Jan 2006
Santa Cruz, CA.
Posts: 3,106
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There are plenty of posts on buckets that blow off the lids so I would use largest diameter tube possible on the bucket. I have read a lot posts about the big fermentations of wheat beers too. The 1\2" tube may work well enough but I don't think the 1\4 " one would be good enough.

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Old 01-12-2007, 04:24 PM   #7
Cregar's Avatar
May 2006
Phoenix, AZ
Posts: 701
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I just brewed a hefeweizen about 2 wweks ago and fermented it in a 6.5 gallon carboy, about 18 hours after pitching yeast the krausen started to come out of the airlock. I had to replace it with a 1" blowoff tube (luckly I caught it before anything bad happened).

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