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Old 05-20-2009, 04:49 AM   #1
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Default Blow Off Confusion

Sorry guys I have never brewed a beer in my life and would really like my first batch to turn out adequate so I have lots of questions

I watched a ton of videos and very few acknowledged blow off. Perhaps this is just a problem certain recipes/setup's have? Anyways Not sure which recipe I plan to brew but I will be using a 6.5 gallon plastic bucket for a 5 gallon batch of beer and my brewing kit comes with a drilled hole and rubber stopper for the airlock but nothing for blow off, I wasn't sure if it was necessary with this size bucket.

Here is the kit I have purchased for reference...

The Home Brewery - Basic Beer Brewing System and Equipment Kit

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Old 05-20-2009, 01:19 PM   #2
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The only way to know if you'll need a blowoff tube is to watch the fermentation Not all of them will require one, but some will. I'd say be prepared for the worst and hope for the best. The 5 feet of tubing that comes with the kit MAY fit in the rubber stopper, but I'm not absolutely sure. If it doesn't, run down to your local hardware store and pick up some that will.

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Old 05-20-2009, 01:35 PM   #3
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A blowoff tube is in lieu of the airlock. You would use an airlock usually as a general practice to create a one way barrier for CO2 to escape during fermentation and not allow nasties to come in. You would substitute the airlock with the blow off tube in the event of overly aggressive fermentations where the airlock just can't keep up with the high krausen or CO2 output. Its really no more than a 'Super' Airlock. Stuff a hose in the hole in your lid where the stopper would normally go and the other end in a jar/container of sanitized liquid to create essentially a large airlock. As schweaty said, you'll just have to keep an eye on the fermentation, but in a 6.5 G bucket I would think you SHOULD be fine...just depends on the OG and the aggressiveness of the yeast
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Old 05-31-2009, 06:54 PM   #4
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Can blowoff be prevented if you use a larger carboy, say 6 gallon instead of 5?
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Old 05-31-2009, 07:00 PM   #5
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6 gallon isn't big enough to ensure that you won't have blow off...

I'm using a 7.8 gallon primary and have had several brew's krausen hit the top of the bucket. The problem occurs if/when an airlock gets clogged with bits of hops or krausen and prevents the gas to escape. A blow off is nothing more than a extra large airlock.

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Old 05-31-2009, 07:02 PM   #6
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Originally Posted by BeerCigars View Post
Can blowoff be prevented if you use a larger carboy, say 6 gallon instead of 5?
With a 6 gallon carboy, and warm temperatures, you're probably going to have to use a blow-off tube for a 5 gallon batch. If you use a 6.5 gallon carboy, you probably have less of a likelihood of needed a blow off tube. Wheat beers and warm temperatures tend to cause more krausen and more vigorous activity, so they more often need a blow-off tube.

I use 7.5 gallon buckets for 5 gallon batches, and never need a blow off tube. I needed one about two years ago, when a fermentation got too warm. That's the only one I ever used, though.

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