Fermentation lock versus blow off tube

If i put a five gallon batch in a six gallon carboy,can I just use an air lock or will i need a blowoff tube? Will the extra space give me enough headroom?
If i need a tube,can i adapt the one from my wine racking cane into the airlock stopper instead of a large 1 1/2 inch tube?


http://s93.photobucket.com/albums/l65/kwrabbit/blowoff tube/

Sure. Just make sure you have a gallon of white ceiling paint handy.

Seriously though, it depends on the beer. With a wheat or some high-gravity beer you're almost guaranteed a blowoff. Even a modest pale ale can can easily exceed that one gallon of head space. Why take the chance? Just use a blowoff untill the krausen starts to fall, then replace with an airlock.

For my blowoff I use a standard 3 piece airlock with the tapered bottom trimmed off (so the gunk can get through) and run a length of tubing from the top of the airlock. (It's either 1/2 in ID or 3/8 in ID, I can't recall.) When the blowoff is done I pull that airlock off and put a fresh one in, no need to remove the stopper.

I added some pics to OP
I think I would rather use the tubing attached to three piece airlock as you suggest or tube adapted to stopper.If I use the first option should I cut the restriction off the bottom of the airlock part? I usually brew wine so it is not an issiue.

buzzbee said:

If I use the first option should I cut the restriction off the bottom of the airlock part? I usually brew wine so it is not an issiue.

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I do. Since I don't filter the wort when I transfer to the primary there is a lot of hop matter and break material that gets transferred over. Without snipping the bottom of the airlock there's a real chance it'd end up plugged. Even after snipping it off I worry that it'll get plugged, but so far it never has.

BTW, your first pic is exactly what I do.

I've only done three batches but learned the hard way to start using a blow off every time at least for the first 3-5 days.

I did a hefe that sprayed krausen all over the living room...twice. Never again

1 1/4" ID tubing at the Depot is like a dollar/something a foot.....Stop by....buy a 3-4 foot piece and never have to worry. ALL of my primaries in the first week get a blow-off tube. I've had some nasty blow-offs...but nothing on the ceiling because of the couple bucks spent....Just MHO....

Once I put on the blow off tube can I put the other end in a gallon jug with the end covered in star san solution or is water better?

buzzbee said:

Once I put on the blow off tube can I put the other end in a gallon jug with the end covered in star san solution or is water better?

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I use a StarSan solution, or maybe Idophor.

Thanks Stunned Monkey,you've been a big help to a new guy with the jitters today.