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Airlock/Blow-off tube question

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Hefanatic

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I recently brewed an Oatmeal Stout. I figured with this brew it would be a good idea to use a blow off tube instead of just an Airlock. This (picture) is what I came up with, using the advice of my LHBS manager. I mixed a 1/2 gallon batch of no-rinse sanitizer in a milk carton. I cut a slit in some transfer tubing and inserted into the middle portion of an airlock. I ran the tubing into the carton of sanitizer and inserted the airlock into the top of my fermenter. Is this trustworthy enough? My buddy recently had the top of his pail blow off with a similar brew and I would like to avoid that at all costs. (Although I feel it is a rite of passage!) Any help is greatly appreciated.

Blow-Off.jpg
 
It might be ok, but the tips of the airlocks sometimes get clogged causing pressure to build and this can blow the top off. You could get some larger diameter tubing and drill a hole in the lid just smaller than the tubing then just insert it directly into the lid. Or use the existing hole minus the grommet.
 
what size fermenter and what is your volume?

5 gal in a 6.5 gal container - no worries

5 gal in a 5.5 gal container - blowoff tube

5 gal in a 3 gal container - miracle of physics and blow off tube required.
 
It might be ok, but the tips of the airlocks sometimes get clogged causing pressure to build and this can blow the top off. You could get some larger diameter tubing and drill a hole in the lid just smaller than the tubing then just insert it directly into the lid. Or use the existing hole minus the grommet.

This airlock has a larger hole than others I have seen. It doesn't have the cross pattern on it like most.
 
what size fermenter and what is your volume?

5 gal in a 6.5 gal container - no worries

5 gal in a 5.5 gal container - blowoff tube

5 gal in a 3 gal container - miracle of physics and blow off tube required.

It is 5 Gallons in a 6.5 Gallon container. (There is roughly 6-8 inches between the top of the wort and the lid)
 
You should be good to go then, enjoy your brew.:mug:

Thanks! Woke up this morning and it was bubbling away. I will have to keep a close eye on it. Seems like you get some warning signs before having an explosion. Chocolate Oatmeal Milk Stout. Fingers crossed!
 
I will definitely make a better blow off tube this weekend. Considering the potential for an explosion I don't see why anyone wouldn't use a blow off tube 100% of the time.
 
I will definitely make a better blow off tube this weekend. Considering the potential for an explosion I don't see why anyone wouldn't use a blow off tube 100% of the time.

Right there with you Hefanatic. I use a blowoff tube for 1 week on every single brew i make. Sometimes more if it's just going crazy.
 
With a blow-off tube should I expect more or less bubbling in my water? I completely understand that water activity or lack thereof is not necessarily indicative of inactive yeast or absence of fermentation. My brew was bubbling like crazy when I woke up the night after I brewed it, but when I got home from work there was no bubbles whatsoever. There is also condensation in the tubing that runs to my sanitizer jug. I am not in the least bit concerned because I have Krausen in the pail. It is about 4 inches above the wort, so it rose pretty good for that 12+ hours. I just don't know what to expect when using a blow off tube. I also used dry yeast for the first time and honestly that was a little concerning with the rehydration part. Any help is greatly appreciated.
 
Re-hydrating dry yeast is def a good thing. It worked pretty good for me. I use the blow off tube/jug set up till initial,mad fermentation is over. Then switch to an airlock. Initial fermentation can be 1-2 days,or 4 days or so. Every ferment is different. I usually get a lot of off gassing with the blow off Some will blow krausen,some just blow a lot of co2. it may be quick,it may last a few days. RDWHAHB...:mug:
 
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