How to make a blow off tube.

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Chippy_Tea

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I always use a blow off tube when using my FV as i have had a couple wines come through the airlock (see picture below) they are also useful if you only have a standard airlock and a vigorous fermentation keeps blowing the liquid out.

They are also much quieter than airlocks.

The how to bit -

Cut the bottom off an airlock then get a short piece of syphon tube and soften one end in boiling water, insert the airlock tube leaving enough sticking out to get a good seal in the FV grommet.

Pour enough water or steriliser into a container (i used a small vinegar bottle - see below) so the other end of the tube is just covered and that's it, you can now empty the container if it gets messy which is a lot easier than cleaning airlocks.

I used some blu-tac to seal the top (leaving a small hole) which keeps the end of the tube in place under the water and nasties out.

I saw this mentioned in another thread after i posted the how to above -

You can also use a standard syphon tube if you have one with a tap as the longer side of the tap is a tight fit in the grommet.

I have also seen people push the syphon tube over the inner part of a Wilko handy airlock.





My version


1586605586355.png


Manxnortons blow off tube in action. (skip to 18 then 42 seconds)

 

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Dutto

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Just three tips to add to the effectiveness of the system:

1. A clear bottle allows you to keep an eye on what is happening and to time the bubbles towards the end of fermentation.

2. The deeper the tube goes below the surface of the liquid the greater the amount of pressure required to blow the bubbles out; so keep the liquid level above the tube to no more than 10mm.

3. Adding a capful of a De-Foaming agent such as this ...

http://www.homebrewcentregy.com/still-spirits-distilling-conditioner-defoaming-agent-50ml

... to the liquid will ensure that a carry-over from the FV won't immediately result in foam being produced and forced out of the bottle.
 

Chippy_Tea

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. The deeper the tube goes below the surface of the liquid the greater the amount of pressure required to blow the bubbles out; so keep the liquid level above the tube to no more than 10mm.
Good tip that Dutto and another benefit that i should have added to the OP is it makes it so much quieter, with 40mm of water in the vinegar bottle the noise it makes drives you mad i found the small quantity you can see in my set up above (first picture) and a small angle cut on one edge of the bottom of the tube makes it very quiet.

.
 

Chippy_Tea

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My Range Make your own Rose wine decided to make a bid for freedom today when i was out of the house, i am so glad i use a blow off tube.

Half an hour after i took this picture it was coming out of the top of the bottle. ashock1

I started the kit less than 24 hours ago so maybe its still too warm in my kitchen for the heat pad, i have made this kit before and have had the occasional blow through but never this early or as vigorous a fermentation .


 
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Dutto

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UPDATE:
  1. I use a ratio of One Unit of Tesco Thin Bleach to Two Units of Water instead of the de-foamer. The bleach is readily available, cheap, stops any foam and also ensures that nothing nasty starts to grow in the Blow Off Bottle.
  2. I use a minimum size of a One Litre bottle. (This was after a brew escaped from a 75cl bottle.)
  3. As previously suggested, I keep the level about 10mm above the bottom of the tube. Towards the end of the fermentation I can slowly lift the tube upwards and if bubbles appear, the brew is still fermenting. Fermentation has stopped (*) when no bubbles appear on two consecutive days.
(*) Assuming that there are no leaks from the system!
 

Chippy_Tea

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Nice one, I use one every time I use the FV for peace of mind and less noise (my FV is in the kitchen) but tend to leave more headspace in my DJ's than you have here as it doesn't really matter if you are not taking hydrometer readings as you can top up later.
 

johncrobinson

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I love the sound of a bloop blooping airlock it helps me sleep.I find with plastic fermeters the bubbles come in batches with the centre of the lid rising and falling.Not so soothing.
I really like this idea as i have often thought the standard airlock was fine for 1gal demijohns but not big enough to handle the output from a 5gal fermenter.
A bit of spry crisp n dry cooking oil will help with foam as it contains an anti foaming agent.
 

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If you only put enough water in the container to cover the end of the tube foaming isn't really a problem, mine in the OP never made it to the top plus you can easily empty it anytime. :thumba:
 

foxy

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I love the sound of a bloop blooping airlock it helps me sleep.I find with plastic fermeters the bubbles come in batches with the centre of the lid rising and falling.Not so soothing.
I really like this idea as i have often thought the standard airlock was fine for 1gal demijohns but not big enough to handle the output from a 5gal fermenter.
A bit of spry crisp n dry cooking oil will help with foam as it contains an anti foaming agent.
Could have been the co2 which helped you sleep, before I had my cool room set up I had 5 fermenters in the bedroom, sort of gave me a Russian roulette feeling as I drifted off to sleep wondering what the odds were of me waking up in the morning.
 

Lostan7

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Hey. I’m a relatively new homebrewer and have just read this forum as found same problem with my 90 shilling brew...! (11ltrs in a 13ltr fermenter.)
Thanks Guys...👍🏼
 

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Going to try this on tonight's effort, Youngs Harvest Pilsner, just waiting for temp to get below 25C before taking OG and adding the yeast(as per pack instructions). If I'd known about this before it might have saved me a lot of angst and cleaning up when my cab sav erupted last month (turned out ok though) Teach me to read through previous posts more diligently. All part of the learning curve
 

Dutto

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If you only put enough water in the container to cover the end of the tube foaming isn't really a problem, mine in the OP never made it to the top plus you can easily empty it anytime.
I agree, but if you put a bit more water in then you can check that the brew has actually finished fermenting.

All you do is wait for the bubbles to stop, then lift the tube up ½ an inch from the bottom and if more bubbles appear then the brew is still fermenting. (This always assumes that there are no leaks around the rim of the FV or the connection to the Blow-Off.)
 

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